National Library of Energy BETA

Sample records for accessibility wind turbulence

  1. Supercomputers Capture Turbulence in the Solar Wind

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

    Capture Turbulence in the Solar Wind Supercomputers Capture Turbulence in the Solar Wind Berkeley Lab visualizations could help scientists forecast destructive space weather...

  2. Energy dissipation processes in solar wind turbulence

    E-Print Network [OSTI]

    Wang, Y; Feng, X S; Xu, X J; Zhang, J; Sun, T R; Zuo, P B

    2015-01-01

    Turbulence is a chaotic flow regime filled by irregular flows. The dissipation of turbulence is a fundamental problem in the realm of physics. Theoretically, dissipation cannot be ultimately achieved without collisions, and so how turbulent kinetic energy is dissipated in the nearly collisionless solar wind is a challenging problem. Wave particle interactions and magnetic reconnection are two possible dissipation mechanisms, but which mechanism dominates is still a controversial topic. Here we analyze the dissipation region scaling around a solar wind magnetic reconnection region. We find that the magnetic reconnection region shows a unique multifractal scaling in the dissipation range, while the ambient solar wind turbulence reveals a monofractal dissipation process for most of the time. These results provide the first observational evidences for the intermittent multifractal dissipation region scaling around a magnetic reconnection site, and they also have significant implications for the fundamental energy...

  3. Turbulent density fluctuations in the solar wind

    E-Print Network [OSTI]

    Ingale, Madhusudan

    2015-01-01

    Treatments of the radio scattering due to density turbulence in the solar wind typically employ asymptotic approximations to the phase structure function. We use a general structure function (GSF) that straddles the asymptotic limits and quantify the relative error introduced by the approximations. We show that the regimes where GSF predictions are accurate than those of its asymptotic approximations is not only of practical relevance, but are where inner scale effects influence the estimate of the scatter-broadening. Thus we propose that GSF should henceforth be used for scatter broadening calculations and estimates of quantities characterizing density turbulence in the solar corona and solar wind. In the next part of this thesis we use measurements of density turbulence in the solar wind from previously publish observations of radio wave scattering and interplanetary scintillations. Density fluctuations are inferred using the GSF for radio scattering data and existing analysis methods for IPS. Assuming that...

  4. Turbulent Wind Fields for Gaseous Phenomena Eugene Fiume 0

    E-Print Network [OSTI]

    Toronto, University of

    Turbulent Wind Fields for Gaseous Phenomena Jos Stam Eugene Fiume 0 Department of Computer Science of smoke, steam, mist and water re­ acting to a turbulent field such as wind is an attractive, and realistic illumina­ tion. We present a model for turbulent wind flow having a deterministic component

  5. RELAXATION PROCESSES IN SOLAR WIND TURBULENCE

    SciTech Connect (OSTI)

    Servidio, S.; Carbone, V.; Gurgiolo, C.; Goldstein, M. L.

    2014-07-10

    Based on global conservation principles, magnetohydrodynamic (MHD) relaxation theory predicts the existence of several equilibria, such as the Taylor state or global dynamic alignment. These states are generally viewed as very long-time and large-scale equilibria, which emerge only after the termination of the turbulent cascade. As suggested by hydrodynamics and by recent MHD numerical simulations, relaxation processes can occur during the turbulent cascade that will manifest themselves as local patches of equilibrium-like configurations. Using multi-spacecraft analysis techniques in conjunction with Cluster data, we compute the current density and flow vorticity and for the first time demonstrate that these localized relaxation events are observed in the solar wind. Such events have important consequences for the statistics of plasma turbulence.

  6. Turbulence of the Solar Wind Studies of the Solar Wind Using the ACE and Helios Spacecraft

    E-Print Network [OSTI]

    provide enough energy to account for the heating of the solar wind relative to an adiabatic expansion Composition Explorer to compute the cascade rate of the turbulence in the solar wind. We nd the energy cascadeTurbulence of the Solar Wind Studies of the Solar Wind Using the ACE and Helios Spacecraft Bejamin

  7. AIAA980057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS

    E-Print Network [OSTI]

    Sweetman, Bert

    AIAA­98­0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS: PARAMETRIC STUDY WITH MULTIPLE that is most useful in estimating fatigue loads on wind turbine blades. The histograms of rainflow counted for flapwise loads on three horizontal axis wind tur­ bines(HAWTs). In the case of two of these turbines

  8. Turbulent heating of the corona and solar wind: the heliospheric

    E-Print Network [OSTI]

    Turbulent heating of the corona and solar wind: the heliospheric dark energy problem Stuart D. Bale that the gas is highly ionized, i.e. a magnetized collisionless plasma ( wind model A `solar wind' is accelerated from the corona - Hydrostatic solution (similar to Bondi accretion

  9. Residual Energy Spectrum of Solar Wind Turbulence

    E-Print Network [OSTI]

    Chen, C H K; Salem, C S; Maruca, B A

    2013-01-01

    It has long been known that the energy in velocity and magnetic field fluctuations in the solar wind is not in equipartition. In this paper, we present an analysis of 5 years of Wind data at 1 AU to investigate the reason for this. The residual energy (difference between energy in velocity and magnetic field fluctuations) was calculated using both the standard magnetohydrodynamic (MHD) normalization for the magnetic field and a kinetic version, which includes temperature anisotropies and drifts between particle species. It was found that with the kinetic normalization, the fluctuations are closer to equipartition, with a mean normalized residual energy of sigma_r = -0.19 and mean Alfven ratio of r_A = 0.71. The spectrum of residual energy, in the kinetic normalization, was found to be steeper than both the velocity and magnetic field spectra, consistent with some recent MHD turbulence predictions and numerical simulations, having a spectral index close to -1.9. The local properties of residual energy and cros...

  10. Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind Turbines

    E-Print Network [OSTI]

    Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind Turbines Torben Mikkelsen, Jakob Mann and Michael Courtney Wind Energy Department, Risø National Laboratory:Torben.Mikkelsen@Risoe.dk Summary RISØ DTU has started to build a newly designed laser-based lidar scanning facility for remote wind

  11. MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

  12. MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND for conditions important for offshore wind energy utilisation are compared and tested: Four models tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

  13. Wind Access and Permitting Law

    Broader source: Energy.gov [DOE]

    The law also defines a limited set of reasonable restrictions that governments and associations are permitted to use in regulating residential wind energy systems. Any limitations put in place may...

  14. Magnetic Discontinuities in Magnetohydrodynamic Turbulence and in the Solar Wind

    E-Print Network [OSTI]

    Vladimir Zhdankin; Stanislav Boldyrev; Joanne Mason; Jean Carlos Perez

    2012-04-19

    Recent measurements of solar wind turbulence report the presence of intermittent, exponentially distributed angular discontinuities in the magnetic field. In this Letter, we study whether such discontinuities can be produced by magnetohydrodynamic (MHD) turbulence. We detect the discontinuities by measuring the fluctuations of the magnetic field direction, Delta theta, across fixed spatial increments Delta x in direct numerical simulations of MHD turbulence with an imposed uniform guide field B_0. A large region of the probability density function (pdf) for Delta theta is found to follow an exponential decay, proportional to exp(-Delta theta/theta_*), with characteristic angle theta_* ~ (14 deg) (b_rms/B_0)^0.65 for a broad range of guide-field strengths. We find that discontinuities observed in the solar wind can be reproduced by MHD turbulence with reasonable ratios of b_rms/B_0. We also observe an excess of small angular discontinuities when Delta x becomes small, possibly indicating an increasing statistical significance of dissipation-scale structures. The structure of the pdf in this case closely resembles the two-population pdf seen in the solar wind. We thus propose that strong discontinuities are associated with inertial-range MHD turbulence, while weak discontinuities emerge from near-dissipation-range turbulence. In addition, we find that the structure functions of the magnetic field direction exhibit anomalous scaling exponents, which indicates the existence of intermittent structures.

  15. Measurement of turbulent wind velocities using a rotating boom apparatus

    SciTech Connect (OSTI)

    Sandborn, V.A.; Connell, J.R.

    1984-04-01

    The present report covers both the development of a rotating-boom facility and the evaluation of the spectral energy of the turbulence measured relative to the rotating boom. The rotating boom is composed of a helicopter blade driven through a pulley speed reducer by a variable speed motor. The boom is mounted on a semiportable tower that can be raised to provide various ratios of hub height to rotor diameter. The boom can be mounted to rotate in either the vertical or horizontal plane. Probes that measure the three components of turbulence can be mounted at any location along the radius of the boom. Special hot-film sensors measured two components of the turbulence at a point directly in front of the rotating blade. By using the probe rotated 90/sup 0/ about its axis, the third turbulent velocity component was measured. Evaluation of the spectral energy distributions for the three components of velocity indicates a large concentration of energy at the rotational frequency. At frequencies slightly below the rotational frequency, the spectral energy is greatly reduced over that measured for the nonrotating case measurements. Peaks in the energy at frequencies that are multiples of the rotation frequency were also observed. We conclude that the rotating boom apparatus is suitable and ready to be used in experiments for developing and testing sensors for rotational measurement of wind velocity from wind turbine rotors. It also can be used to accurately measure turbulent wind for testing theories of rotationally sampled wind velocity.

  16. A Tree Swaying in a Turbulent Wind: A Scaling Analysis

    E-Print Network [OSTI]

    Theo Odijk

    2014-07-10

    A tentative scaling theory is presented of a tree swaying in a turbulent wind. It is argued that the turbulence of the air within the crown is in the inertial regime. An eddy causes a dynamic bending response of the branches according to a time criterion. The resulting expression for the penetration depth of the wind yields an exponent which appears to be consistent with that pertaining to the morphology of the tree branches. An energy criterion shows that the dynamics of the branches is basically passive. The possibility of hydrodynamic screening by the leaves is discussed.

  17. Residual energy in magnetohydrodynamic turbulence and in the solar wind

    E-Print Network [OSTI]

    Stanislav Boldyrev; Jean Carlos Perez; Vladimir Zhdankin

    2011-08-30

    Recent observations indicate that kinetic and magnetic energies are not in equipartition in the solar wind turbulence. Rather, magnetic fluctuations are more energetic and have somewhat steeper energy spectrum compared to the velocity fluctuations. This leads to the presence of the so-called residual energy E_r=E_v-E_b in the inertial interval of turbulence. This puzzling effect is addressed in the present paper in the framework of weak turbulence theory. Using a simple model of weakly colliding Alfv\\'en waves, we demonstrate that the kinetic-magnetic equipartition indeed gets broken as a result of nonlinear interaction of Alfv\\'en waves. We establish that magnetic energy is indeed generated more efficiently as a result of these interactions, which proposes an explanation for the solar wind observations.

  18. RECONNECTION OUTFLOW GENERATED TURBULENCE IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Vörös, Z.; Sasunov, Y. L.; Zaqarashvili, T. V.; Khodachenko, M.; Semenov, V. S.; Bruno, R.

    2014-12-10

    Petschek-type time-dependent reconnection (TDR) and quasi-stationary reconnection (QSR) models are considered to understand reconnection outflow structures and the generation of local turbulence in the solar wind. Comparing TDR/QSR model predictions of the outflow structures with actual measurements shows that both models can explain the data equally well. It is demonstrated that the outflows can often generate more or less spatially extended turbulent boundary layers. The structure of a unique extended reconnection outflow is investigated in detail. The analysis of spectral scalings and spectral break locations shows that reconnection can change the local field and plasma conditions which may support different local turbulent dissipation mechanisms at their characteristic wavenumbers.

  19. Dissipation-Scale Turbulence in the Solar Wind

    E-Print Network [OSTI]

    Gregory G. Howes; Steven C. Cowley; William Dorland; Gregory W. Hammett; Eliot Quataert; Alexander A. Schekochihin

    2007-07-20

    We present a cascade model for turbulence in weakly collisional plasmas that follows the nonlinear cascade of energy from the large scales of driving in the MHD regime to the small scales of the kinetic Alfven wave regime where the turbulence is dissipated by kinetic processes. Steady-state solutions of the model for the slow solar wind yield three conclusions: (1) beyond the observed break in the magnetic energy spectrum, one expects an exponential cut-off; (2) the widely held interpretation that this dissipation range obeys power-law behavior is an artifact of instrumental sensitivity limitations; and, (3) over the range of parameters relevant to the solar wind, the observed variation of dissipation range spectral indices from -2 to -4 is naturally explained by the varying effectiveness of Landau damping, from an undamped prediction of -7/3 to a strongly damped index around -4.

  20. "Complexity" Induced Plasma Turbulence in Coronal Holes and the Solar Wind

    E-Print Network [OSTI]

    that are generally detected in the solar wind [10]. We also address the concept of resonant energization of solar"Complexity" Induced Plasma Turbulence in Coronal Holes and the Solar Wind Tom Chang Center that plasma turbulence emanating from coronal holes may efficiently accelerate the solar wind to observed

  1. On the Study of Uncertainty in Inflow Turbulence Model Parameters in Wind Turbine Applications

    E-Print Network [OSTI]

    Manuel, Lance

    On the Study of Uncertainty in Inflow Turbulence Model Parameters in Wind Turbine Applications Korn, Austin, TX 78712 In stochastic simulation of inflow turbulence random fields for wind turbine applica variables forms the basis of this study. A commercial-sized 1.5MW concept wind turbine is considered

  2. On the use of proper orthogonal decomposition to describe inflow turbulence and wind turbine loads

    E-Print Network [OSTI]

    Manuel, Lance

    On the use of proper orthogonal decomposition to describe inflow turbulence and wind turbine loads, USA Keywords: Proper Orthogonal Decomposition, inflow turbulence, wind turbine ABSTRACT: We discuss experienced by a wind turbine. A methodology is proposed that employs low- dimensional POD models

  3. Observation of Turbulent Intermittency Scaling with Magnetic Helicity in an MHD Plasma Wind Tunnel

    E-Print Network [OSTI]

    Brown, Michael R.

    Observation of Turbulent Intermittency Scaling with Magnetic Helicity in an MHD Plasma Wind Tunnel. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays. Differences in magnetic intermittent character have been seen between fast and slow solar wind turbulence [2

  4. Three-fluid, three-dimensional magnetohydrodynamic solar wind model with eddy viscosity and turbulent resistivity

    SciTech Connect (OSTI)

    Usmanov, Arcadi V.; Matthaeus, William H.; Goldstein, Melvyn L.

    2014-06-10

    We have developed a three-fluid, three-dimensional magnetohydrodynamic solar wind model that incorporates turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a system of co-moving solar wind protons, electrons, and interstellar pickup protons, with separate energy equations for each species. Numerical steady-state solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations for turbulence energy, cross helicity, and correlation length are obtained by the time relaxation method in the corotating with the Sun frame of reference in the region from 0.3 to 100 AU (but still inside the termination shock). The model equations include the effects of electron heat conduction, Coulomb collisions, photoionization of interstellar hydrogen atoms and their charge exchange with the solar wind protons, turbulence energy generation by pickup protons, and turbulent heating of solar wind protons and electrons. The turbulence transport model is based on the Reynolds decomposition and turbulence phenomenologies that describe the conversion of fluctuation energy into heat due to a turbulent cascade. In addition to using separate energy equations for the solar wind protons and electrons, a significant improvement over our previous work is that the turbulence model now uses an eddy viscosity approximation for the Reynolds stress tensor and the mean turbulent electric field. The approximation allows the turbulence model to account for driving of turbulence by large-scale velocity gradients. Using either a dipole approximation for the solar magnetic field or synoptic solar magnetograms from the Wilcox Solar Observatory for assigning boundary conditions at the coronal base, we apply the model to study the global structure of the solar wind and its three-dimensional properties, including embedded turbulence, heating, and acceleration throughout the heliosphere. The model results are compared with plasma and magnetic field observations on WIND, Ulysses, and Voyager 2 spacecraft.

  5. Surface-Layer Wind and Turbulence Profiling from LIDAR: Theory and Measurements

    E-Print Network [OSTI]

    Surface-Layer Wind and Turbulence Profiling from LIDAR: Theory and Measurements Régis DANIELIAN (Vestas Wind System) Hans Ejsing JØRGENSEN (Wind Energy Department, Risø. Contact: haej@risoe.dk) Torben MIKKELSEN (Wind Energy Department, Risø. Contact: tomi@risoe.dk) Jacob MANN (Wind Energy Department, Risø

  6. Solar Wind Turbulence A Study of Corotating Interaction Regions at 1 AU

    E-Print Network [OSTI]

    Solar Wind Turbulence A Study of Corotating Interaction Regions at 1 AU Je rey A. Tessein Department of Physics University of New Hampshire Durham, NH 03824 May 15, 2009 #12;Abstract The solar wind's rotation and the variability in the source of the solar wind, fast moving wind can crash into slow wind

  7. REVIEW Open Access Assessing environmental impacts of offshore wind

    E-Print Network [OSTI]

    Aberdeen, University of

    REVIEW Open Access Assessing environmental impacts of offshore wind farms: lessons learned and recommendations for the future Helen Bailey1* , Kate L Brookes2 and Paul M Thompson3 Abstract Offshore wind power literature and our experience with assessing impacts of offshore wind developments on marine mammals

  8. Predicted Impacts of Proton Temperature Anisotropy on Solar Wind Turbulence

    E-Print Network [OSTI]

    Klein, Kristopher G

    2015-01-01

    Particle velocity distributions measured in the weakly collisional solar wind are frequently found to be non-Maxwellian, but how these non-Maxwellian distributions impact the physics of plasma turbulence in the solar wind remains unanswered. Using numerical solutions of the linear dispersion relation for a collisionless plasma with a bi-Maxwellian proton velocity distribution, we present a unified framework for the four proton temperature anisotropy instabilities, identifying the associated stable eigenmodes, highlighting the unstable region of wavevector space, and presenting the properties of the growing eigenfunctions. Based on physical intuition gained from this framework, we address how the proton temperature anisotropy impacts the nonlinear dynamics of the \\Alfvenic fluctuations underlying the dominant cascade of energy from large to small scales and how the fluctuations driven by proton temperature anisotropy instabilities interact nonlinearly with each other and with the fluctuations of the large-scal...

  9. Electron and proton heating by solar wind turbulence B. Breech,1

    E-Print Network [OSTI]

    Oughton, Sean

    magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate internal energy equations for electronsElectron and proton heating by solar wind turbulence B. Breech,1 W. H. Matthaeus,2 S. R. Cranmer,3 and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both

  10. Small Scale Energy Cascade of the Solar Wind Turbulence

    E-Print Network [OSTI]

    O. Alexandrova; V. Carbone; P. Veltri; L. Sorriso-Valvo

    2007-10-03

    Magnetic fluctuations in the solar wind are distributed according to Kolmogorov's power law $f^{-5/3}$ below the ion cyclotron frequency $f_{ci}$. Above this frequency, the observed steeper power law is usually interpreted in two different ways: a dissipative range of the solar wind turbulence or another turbulent cascade, the nature of which is still an open question. Using the Cluster magnetic data we show that after the spectral break the intermittency increases toward higher frequencies, indicating the presence of non-linear interactions inherent to a new inertial range and not to the dissipative range. At the same time the level of compressible fluctuations raises. We show that the energy transfer rate and intermittency are sensitive to the level of compressibility of the magnetic fluctuations within the small scale inertial range. We conjecture that the time needed to establish this inertial range is shorter than the eddy-turnover time, and is related to dispersive effects. A simple phenomenological model, based on the compressible Hall MHD, predicts the magnetic spectrum $\\sim k^{-7/3+2\\alpha}$, which depends on the degree of plasma compression $\\alpha$.

  11. Proton Heating in Solar Wind Compressible Turbulence with Collisions between Counter-propagating Waves

    E-Print Network [OSTI]

    He, Jiansen; Marsch, Eckart; Chen, Christopher H K; Wang, Linghua; Pei, Zhongtian; Zhang, Lei; Salem, Chadi S; Bale, Stuart D

    2015-01-01

    Magnetohydronamic turbulence is believed to play a crucial role in heating the laboratorial, space, and astrophysical plasmas. However, the precise connection between the turbulent fluctuations and the particle kinetics has not yet been established. Here we present clear evidence of plasma turbulence heating based on diagnosed wave features and proton velocity distributions from solar wind measurements by the Wind spacecraft. For the first time, we can report the simultaneous observation of counter-propagating magnetohydrodynamic waves in the solar wind turbulence. Different from the traditional paradigm with counter-propagating Alfv\\'en waves, anti-sunward Alfv\\'en waves (AWs) are encountered by sunward slow magnetosonic waves (SMWs) in this new type of solar wind compressible turbulence. The counter-propagating AWs and SWs correspond respectively to the dominant and sub-dominant populations of the imbalanced Els\\"asser variables. Nonlinear interactions between the AWs and SMWs are inferred from the non-orth...

  12. Simulating Turbulent Wind Fields for Offshore Turbines in Hurricane-Prone Regions (Poster)

    SciTech Connect (OSTI)

    Guo, Y.; Damiani, R.; Musial, W.

    2014-04-01

    Extreme wind load cases are one of the most important external conditions in the design of offshore wind turbines in hurricane prone regions. Furthermore, in these areas, the increase in load with storm return-period is higher than in extra-tropical regions. However, current standards have limited information on the appropriate models to simulate wind loads from hurricanes. This study investigates turbulent wind models for load analysis of offshore wind turbines subjected to hurricane conditions. Suggested extreme wind models in IEC 61400-3 and API/ABS (a widely-used standard in oil and gas industry) are investigated. The present study further examines the wind turbine response subjected to Hurricane wind loads. Three-dimensional wind simulator, TurbSim, is modified to include the API wind model. Wind fields simulated using IEC and API wind models are used for an offshore wind turbine model established in FAST to calculate turbine loads and response.

  13. AIAA-98-0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS

    E-Print Network [OSTI]

    Sweetman, Bert

    AIAA-98-0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS: PARAMETRIC STUDY WITH MULTIPLE that is most useful in estimating fatigue loads on wind turbine blades. The histograms of rain ow counted for apwise loads on three horizontal axis wind tur- binesHAWTs. In the case of two of these turbines

  14. A Comparison of Wind Turbine Load Statistics for Inflow Turbulence Fields based on Conventional

    E-Print Network [OSTI]

    Manuel, Lance

    A Comparison of Wind Turbine Load Statistics for Inflow Turbulence Fields based on Conventional for a utility-scale 5MW wind turbine. Load statistics, spectra, and time-frequency analysis representations utility-scale wind turbines. The present study takes on this question by making use of conventional

  15. Turbulence in vertical axis wind turbine canopies Matthias Kinzel, Daniel B. Araya, and John O. Dabiri

    E-Print Network [OSTI]

    Faraon, Andrei

    Turbulence in vertical axis wind turbine canopies Matthias Kinzel, Daniel B. Araya, and John O of a hydroformed metal blade for vertical-axis wind turbines J. Renewable Sustainable Energy 7, 043135 (2015); 10 blades for a vertical axis wind turbine J. Renewable Sustainable Energy 3, 013106 (2011); 10

  16. Modeling access to wind resources in the United States

    SciTech Connect (OSTI)

    Short, W.D.

    1999-10-20

    To project the US potential to meet future electricity demands with wind energy, estimates of available wind resource and costs to access that resource are critical. The US Department of Energy (DOE) Energy Information Administration (EIA) annually estimates the US market penetration of wind in its Annual Energy Outlook series. For these estimates, the EIA uses wind resource data developed by the Pacific Northwest National Laboratory for each region of the country. However, the EIA multiplies the cost of windpower by several factors, some as large as 3, to account for resource quality, market factors associated with accessing the resource, electric grid impacts, and rapid growth in the wind industry. This paper examines the rationale behind these additional costs and suggests alternatives.

  17. Turbulence loads on the Howden 26-m-diameter wind turbine

    SciTech Connect (OSTI)

    Madsen, P.H.; Hock, S.M.; Hausfeld, T.E.

    1987-11-01

    Conducted in Palm Springs, California, a joint effort between SERI and James Howden and Company involved a comprehensive test program on the 330-kW Howden wind turbine with a three-bladed, fixed-hub rotor 26 m in diameter. Part of the measurement analysis is to quantify the turbulence loads during the steady-state production modes of operation. Assuming wind turbulence to be the cause of the random loads, the turbulence loads in terms of blade root-bending moments have been determined empirically by isolating the random or nonperiodic part of the load signals using azimuthal averaging. Standard deviations as functions of wind speed, as well as power spectra of the loads, are presented. The measured turbulence loads are compared to a recently developed model for turbulence loading of wind turbines. The model works in the frequency domain and uses the standard engineering representation of turbulence in terms of a coherence function and a wind-power spectrum at a fixed point in space. The turbulence load model accounts for the dominant mode of vibration for the load in question and is intended to be simple enough to be used for a preliminary load estimate for practical design purposes.

  18. Anisotropy of Imbalanced Alfvenic Turbulence in Fast Solar Wind R. T. Wicks,1,* T. S. Horbury,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    energy to yet smaller scales [3­5]. In the fast wind, the turbulence is imbalanced: there is more power solar wind [8] and from numerical simulations [9] that balanced tur- bulence is made up of locallyAnisotropy of Imbalanced Alfve´nic Turbulence in Fast Solar Wind R. T. Wicks,1,* T. S. Horbury,1 C

  19. On the Loss of Wind-Induced Near-Inertial Energy to Turbulent Mixing in the Upper Ocean

    E-Print Network [OSTI]

    Miami, University of

    On the Loss of Wind-Induced Near-Inertial Energy to Turbulent Mixing in the Upper Ocean XIAOMING received 27 March 2009, in final form 23 June 2009) ABSTRACT Wind-induced near-inertial energy has been find that nearly 70% of the wind-induced near-inertial energy at the sea surface is lost to turbulent

  20. Four-Field Equations: a New Model for Weakly Compressible MHD Turbulence in the Solar Wind and the Interstellar Medium

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Four-Field Equations: a New Model for Weakly Compressible MHD Turbulence in the Solar Wind Flight Center Turbulent plasmas in the solar wind and the interstellar medium of- ten contain a large to be in agreement. The scaling of density uctuations with Mach number are compared with solar wind data from Helios

  1. A study of clear-air turbulence from detailed wind profiles over Cape Kennedy, Florida 

    E-Print Network [OSTI]

    Blackburn, James Harvey

    1969-01-01

    A STUDY OF CLEAR-AIR TURBULENCE FROM DETAII. ED WIND PROFILES OVER CAPE KENNEDY, FLORIDA A Thesis by James Harvey Blackburn, Jr. Captain United States Air Force Approved as to style and content by: (Chairman of ittee) (Head of Dep tment...) (Amber) (Member) May 1969 ABSTRACT A Study of Clear-Air Turbulence from Detailed Wind Profiles Over Cape Kennedy, Florida. James H. Blackburn, Jr. , B. S. , Texas A6N University Directed by: Dr. James R. Scoggins Clear-air turbulence (CAT...

  2. Wind Energy and the Turbulent Nature of the Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Wächter, Matthias; Hölling, Michael; Morales, Allan; Milan, Patrick; Mücke, Tanja; Peinke, Joachim; Reinke, Nico; Rinn, Philip

    2012-01-01

    The challenge of developing a sustainable and renewable energy supply within the next decades requires collaborative efforts as well as new concepts in the fields of science and engineering. Here we give an overview on the impact of small-scale properties of atmospheric turbulence on the wind energy conversion process. Special emphasis is given to the noisy and intermittent structure of turbulence and its outcome for wind energy conversion and utilization. Experimental, theoretical, analytical, and numerical concepts and methods are presented. In particular we report on new aspects resulting from the combination of basic research, especially in the field of turbulence and complex stochastic systems, with engineering applications.

  3. ENHANCED DISSIPATION RATE OF MAGNETIC FIELD IN STRIPED PULSAR WINDS BY THE EFFECT OF TURBULENCE

    SciTech Connect (OSTI)

    Takamoto, Makoto [Department of Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Inoue, Tsuyoshi [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Chuou-ku, Sagamihara 252-5258 (Japan); Inutsuka, Shu-ichiro, E-mail: takamoto@tap.scphys.kyoto-u.ac.jp, E-mail: inouety@phys.aoyama.ac.jp, E-mail: inutsuka@nagoya-u.jp [Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    2012-08-10

    In this paper, we report on turbulent acceleration of the dissipation of the magnetic field in the post-shock region of a Poynting flux-dominated flow, such as the Crab pulsar wind nebula. We have performed two-dimensional resistive relativistic magnetohydrodynamics simulations of subsonic turbulence driven by the Richtmyer-Meshkov instability at the shock fronts of the Poynting flux-dominated flows in pulsar winds. We find that turbulence stretches current sheets which substantially enhances the dissipation of the magnetic field, and that most of the initial magnetic field energy is dissipated within a few eddy-turnover times. We also develop a simple analytical model for turbulent dissipation of the magnetic field that agrees well with our simulations. The analytical model indicates that the dissipation rate does not depend on resistivity even in the small resistivity limit. Our findings can possibly alleviate the {sigma}-problem in the Crab pulsar wind nebulae.

  4. A Two-component Transport Model for Solar Wind Fluctuations: Waves plus Quasi-2D Turbulence

    E-Print Network [OSTI]

    Oughton, Sean

    component. Thus, it would seem appropriate, and advantageous, to develop an energy-containing style modelA Two-component Transport Model for Solar Wind Fluctuations: Waves plus Quasi-2D Turbulence Sean for the transport of solar wind fluctuations, based on the assumption that they can be well-represented using two

  5. Impact of Coherent Turbulence on Wind Turbine Aeroelastic Response and Its Simulation: Preprint

    SciTech Connect (OSTI)

    Kelley, N. D.; Jonkman, B. J.; Scott, G. N.; Bialasiewicz, J. T.; Redmond, L. S.

    2005-08-01

    In this paper, we present a brief overview of our recent research results regarding the impact of organized or coherent inflow turbulence on the dynamic response of operating wind turbines. Previous field experimentation has demonstrated that the greatest structural fatigue damage tends to occur during the nighttime hours from coherent turbulence that develops in the stable, nocturnal atmospheric boundary layer. We have found that under such conditions, intense vertical wind shear and temperature gradients create resonant flow fields that are capable of imparting short-period loading and vibrational energy as wind turbine rotor blades pass through regions of organized or coherent turbulence. This energy is subsequently propagated throughout the remainder of the structure, where it is often locally dissipated. We also briefly discuss our recent progress in developing a numerical simulation that includes such coherent inflow conditions that can be used to excite wind turbine design codes.

  6. Analyzing Effects of Turbulence on Power Generation Using Wind Plant Monitoring Data: Preprint

    SciTech Connect (OSTI)

    Zhang, J.; Chowdhury, S.; Hodge, B. M.

    2014-01-01

    In this paper, a methodology is developed to analyze how ambient and wake turbulence affects the power generation of a single wind turbine within an array of turbines. Using monitoring data from a wind power plant, we selected two sets of wind and power data for turbines on the edge of the wind plant that resemble (i) an out-of-wake scenario (i.e., when the turbine directly faces incoming winds) and (ii) an in-wake scenario (i.e., when the turbine is under the wake of other turbines). For each set of data, two surrogate models were then developed to represent the turbine power generation (i) as a function of the wind speed; and (ii) as a function of the wind speed and turbulence intensity. Support vector regression was adopted for the development of the surrogate models. Three types of uncertainties in the turbine power generation were also investigated: (i) the uncertainty in power generation with respect to the published/reported power curve, (ii) the uncertainty in power generation with respect to the estimated power response that accounts for only mean wind speed; and (iii) the uncertainty in power generation with respect to the estimated power response that accounts for both mean wind speed and turbulence intensity. Results show that (i) under the same wind conditions, the turbine generates different power between the in-wake and out-of-wake scenarios, (ii) a turbine generally produces more power under the in-wake scenario than under the out-of-wake scenario, (iii) the power generation is sensitive to turbulence intensity even when the wind speed is greater than the turbine rated speed, and (iv) there is relatively more uncertainty in the power generation under the in-wake scenario than under the out-of-wake scenario.

  7. DOE-Funded Project Develops Safer Access to Offshore Wind Turbine...

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

    DOE-Funded Project Develops Safer Access to Offshore Wind Turbine Platforms DOE-Funded Project Develops Safer Access to Offshore Wind Turbine Platforms September 10, 2015 - 6:21pm...

  8. The turbulent cascade and proton heating in the solar wind during solar minimum

    SciTech Connect (OSTI)

    Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

    2013-06-13

    Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

  9. THE TURBULENT CASCADE AND PROTON HEATING IN THE SOLAR WIND DURING SOLAR MINIMUM

    SciTech Connect (OSTI)

    Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A. E-mail: Charles.Smith@unh.edu E-mail: Joshua.Stawarz@Colorado.edu

    2012-08-01

    The recently protracted solar minimum provided years of interplanetary data that were largely absent in any association with observed large-scale transient behavior on the Sun. With large-scale shear at 1 AU generally isolated to corotating interaction regions, it is reasonable to ask whether the solar wind is significantly turbulent at this time. We perform a series of third-moment analyses using data from the Advanced Composition Explorer. We show that the solar wind at 1 AU is just as turbulent as at any other time in the solar cycle. Specifically, the turbulent cascade of energy scales in the same manner proportional to the product of wind speed and temperature. Energy cascade rates during solar minimum average a factor of 2-4 higher than during solar maximum, but we contend that this is likely the result of having a different admixture of high-latitude sources.

  10. E-LETTER Earth Planets Space, 65, e5e8, 2013 Doppler shift and broadening in solar wind turbulence

    E-Print Network [OSTI]

    and broadening using magnetic field data in solar wind turbulence. A model of the energy spectrum is constructedE-LETTER Earth Planets Space, 65, e5­e8, 2013 Doppler shift and broadening in solar wind turbulence extraterrestrische Physik, Technische Universit¨at Braunschweig, Mendelssohnstr. 3, D-38106, Germany 3Max

  11. ATMOSPHERIC TURBULENCE MODELING AND IMPLICATIONS FOR WIND ENERGY

    E-Print Network [OSTI]

    Chow, Fotini Katopodes

    @berkeley.edu Abstract The near-surface structure of atmospheric turbu- lence affects the design and operation of wind may pro- vide untapped resources for wind power extraction. This study uses large-eddy simulation (LES- ameters of 80-120 m. Current operational practices for wind farm operation and siting rely on power law

  12. Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint

    SciTech Connect (OSTI)

    Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

    2011-12-01

    Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

  13. The Complex Structure of Magnetic Field Discontinuities in the Turbulent Solar Wind

    E-Print Network [OSTI]

    Greco, A; Servidio, S; Yordanova, E; Veltri, P

    2015-01-01

    Using high resolution Cluster satellite observations, we show that the turbulent solar wind is populated by magnetic discontinuities at different scales, going from proton down to electron scales. The structure of these layers resembles the Harris equilibrium profile in plasmas. Using a multi-dimensional intermittency technique, we show that these structures are connected through the scales. Supported by numerical simulations of magnetic reconnection, we show that observations are consistent with a scenario where many current layers develop in turbulence, and where the outflow of these reconnection events are characterized by complex sub-proton networks of secondary islands, in a self-similar way. The present work establishes that the picture of "reconnection in turbulence" and "turbulent reconnection", separately invoked as ubiquitous, coexist in space plasmas.

  14. Covariance statistics of turbulence velocity components for wind-energy-conversion system design-homogeneous, isotropic case

    SciTech Connect (OSTI)

    Fichtl, G.H.

    1983-09-01

    When designing a wind energy converison system (WECS), it may be necessary to take into account the distribution of wind across the disc of rotation. The specific engineering applications include structural strength, fatigue, and control. This wind distribution consists of two parts, namely that associated with the mean wind profile and that associated with the turbulence velocity fluctuation field. The work reported herein is aimed at the latter, namely the distribution of turbulence velocity fluctuations across the WECS disk of rotation. A theory is developed for the two-time covariance matrix for turbulence velocity vector components for wind energy conversion system (WECS) design. The theory is developed for homogeneous and iotropic turbulance with the assumption that Taylor's hypothesis is valid. The Eulerian turbulence velocity vector field is expanded about the hub of the WECS. Formulae are developed for the turbulence velocity vector component covariance matrix following the WECS blade elements. It is shown that upon specification of the turbulence energy spectrum function and the WECS rotation rate, the two-point, two-time covariance matrix of the turbulent flow relative to the WECS bladed elements is determined. This covariance matrix is represented as the sum of nonstationary and stationary contributions. Generalized power spectral methods are used to obtain two-point, double frequency power spectral density functions for the turbulent flow following the blade elements. The Dryden turbulence model is used to demonstrate the theory. A discussion of linear system response analysis is provided to show how the double frequency turbulence spectra might be used to calculate response spectra of a WECS to turbulent flow. Finally the spectrum of the component of turbulence normal to the WECS disc of rotation, following the blade elements, is compared with experimental results.

  15. Nonlinear and linear timescales near kinetic scales in solar wind turbulence

    SciTech Connect (OSTI)

    Matthaeus, W. H.; Wan, M.; Shay, M. A.; Oughton, S.; Osman, K. T.; Chapman, S. C.; Servidio, S.; Valentini, F.; Gary, S. P.; Roytershteyn, V.; Karimabadi, H.

    2014-08-01

    The application of linear kinetic treatments to plasma waves, damping, and instability requires favorable inequalities between the associated linear timescales and timescales for nonlinear (e.g., turbulence) evolution. In the solar wind these two types of timescales may be directly compared using standard Kolmogorov-style analysis and observational data. The estimated local (in scale) nonlinear magnetohydrodynamic cascade times, evaluated as relevant kinetic scales are approached, remain slower than the cyclotron period, but comparable to or faster than the typical timescales of instabilities, anisotropic waves, and wave damping. The variation with length scale of the turbulence timescales is supported by observations and simulations. On this basis the use of linear theory—which assumes constant parameters to calculate the associated kinetic rates—may be questioned. It is suggested that the product of proton gyrofrequency and nonlinear time at the ion gyroscales provides a simple measure of turbulence influence on proton kinetic behavior.

  16. Proton Kinetic Effects and Turbulent Energy Cascade Rate in the Solar Wind

    E-Print Network [OSTI]

    Osman, Kareem T; Kiyani, Khurom H; Hnat, Bogdan; Chapman, Sandra C

    2013-01-01

    The first observed connection between kinetic instabilities driven by proton temperature anisotropy and estimated energy cascade rates in the turbulent solar wind is reported using measurements from the Wind spacecraft at 1 AU. We find enhanced cascade rates are concentrated along the boundaries of the ($\\beta_{\\parallel}$, $T_{\\perp}/T_{\\parallel}$)-plane, which includes regions theoretically unstable to the mirror and firehose instabilities. A strong correlation is observed between the estimated cascade rate and kinetic effects such as temperature anisotropy and plasma heating, resulting in protons 5-6 times hotter and 70-90% more anisotropic than under typical isotropic plasma conditions. These results offer new insights into kinetic processes in a turbulent regime.

  17. Wind reversals in turbulent Rayleigh-Benard convection

    E-Print Network [OSTI]

    Francisco Fontenele Araujo; S. Grossmann; D. Lohse

    2005-08-29

    The phenomenon of irregular cessation and subsequent reversal of the large-scale circulation in turbulent Rayleigh-B\\'enard convection is theoretically analysed. The force and thermal balance on a single plume detached from the thermal boundary layer yields a set of coupled nonlinear equations, whose dynamics is related to the Lorenz equations. For Prandtl and Rayleigh numbers in the range $10^{-2} \\leq \\Pr \\leq 10^{3}$ and $10^{7} \\leq \\Ra \\leq 10^{12}$, the model has the following features: (i) chaotic reversals may be exhibited at Ra $\\geq 10^{7}$; (ii) the Reynolds number based on the root mean square velocity scales as $\\Re_{rms} \\sim \\Ra^{[0.41 ... 0.47]}$ (depending on Pr), and as $\\Re_{rms} \\sim \\Pr^{-[0.66 ... 0.76]}$ (depending on Ra); and (iii) the mean reversal frequency follows an effective scaling law $\\omega / (\

  18. Heat flux scaling in turbulent Rayleigh-Bénard convection with an imposed longitudinal wind

    E-Print Network [OSTI]

    Andrea Scagliarini; Armann Gylfason; Federico Toschi

    2013-11-19

    We present a numerical study of Rayleigh-B\\'enard convection disturbed by a longitudinal wind. Our results show that under the action of the wind, the vertical heat flux through the cell initially decreases, due to the mechanism of plumes-sweeping, and then increases again when turbulent forced convection dominates over the buoyancy. As a result, the Nusselt number is a non-monotonic function of the shear Reynolds number. We provide a simple model that captures with good accuracy all the dynamical regimes observed. We expect that our findings can lead the way to a more fundamental understanding of the of the complex interplay between mean-wind and plumes ejection in the Rayleigh-B\\'enard phenomenology.

  19. Nonlinear interaction of proton whistler with kinetic Alfvén wave to study solar wind turbulence

    SciTech Connect (OSTI)

    Goyal, R.; Sharma, R. P.; Goldstein, M. L.; Dwivedi, N. K.

    2013-12-15

    This paper presents the nonlinear interaction between small but finite amplitude kinetic Alfvén wave (KAW) and proton whistler wave using two-fluid model in intermediate beta plasma, applicable to solar wind. The nonlinearity is introduced by modification in the background density. This change in density is attributed to the nonlinear ponderomotive force due to KAW. The solutions of the model equations, governing the nonlinear interaction (and its effect on the formation of localized structures), have been obtained using semi-analytical method in solar wind at 1AU. It is concluded that the KAW properties significantly affect the threshold field required for the filament formation and their critical size (for proton whistler). The magnetic and electric field power spectra have been obtained and their relevance with the recent observations of solar wind turbulence by Cluster spacecraft has been pointed out.

  20. Evolution of turbulence in the expanding solar wind, a numerical study

    SciTech Connect (OSTI)

    Dong, Yue; Grappin, Roland; Verdini, Andrea E-mail: verdini@arcetri.astro.it

    2014-10-01

    We study the evolution of turbulence in the solar wind by solving numerically the full three-dimensional (3D) magnetohydrodynamic (MHD) equations embedded in a radial mean wind. The corresponding equations (expanding box model or EBM) have been considered earlier but never integrated in 3D simulations. Here, we follow the development of turbulence from 0.2 AU up to about 1.5 AU. Starting with isotropic spectra scaling as k {sup –1}, we observe a steepening toward a k {sup –5/3} scaling in the middle of the wave number range and formation of spectral anisotropies. The advection of a plasma volume by the expanding solar wind causes a non-trivial stretching of the volume in directions transverse to radial and the selective decay of the components of velocity and magnetic fluctuations. These two effects combine to yield the following results. (1) Spectral anisotropy: gyrotropy is broken, and the radial wave vectors have most of the power. (2) Coherent structures: radial streams emerge that resemble the observed microjets. (3) Energy spectra per component: they show an ordering in good agreement with the one observed in the solar wind at 1 AU. The latter point includes a global dominance of the magnetic energy over kinetic energy in the inertial and f {sup –1} range and a dominance of the perpendicular-to-the-radial components over the radial components in the inertial range. We conclude that many of the above properties are the result of evolution during transport in the heliosphere, and not just the remnant of the initial turbulence close to the Sun.

  1. WHERE DOES FLUID-LIKE TURBULENCE BREAK DOWN IN THE SOLAR WIND?

    SciTech Connect (OSTI)

    Perri, S.; Carbone, V.; Veltri, P.

    2010-12-10

    Power spectra of the magnetic field in solar wind display a Kolmogorov law f {sup -5/3} at intermediate range of frequencies f, say within the inertial range. Two spectral breaks are also observed: one separating the inertial range from an f {sup -1} spectrum at lower frequencies, and another one between the inertial range and an f {sup -7/3} spectrum at higher frequencies. The breaking of fluid-like turbulence at high frequencies has been attributed to either the occurrence of kinetic Alfven wave fluctuations above the ion-cyclotron frequency or to whistler turbulence above the frequency corresponding to the proton gyroradius. Using solar wind data, we show that the observed high-frequency spectral break seems to be independent of the distance from the Sun, and then of both the ion-cyclotron frequency and the proton gyroradius. We suppose that the observed high-frequency break could be either caused by a combination of different physical processes or associated with a remnant signature of coronal turbulence.

  2. Chemical evolution of protoplanetary disks - the effects of viscous accretion, turbulent mixing and disk winds

    E-Print Network [OSTI]

    Heinzeller, Dominikus; Walsh, Catherine; Millar, Tom J

    2011-01-01

    We calculate the chemical evolution of protoplanetary disks considering radial viscous accretion, vertical turbulent mixing and vertical disk winds. We study the effects on the disk chemical structure when different models for the formation of molecular hydrogen on dust grains are adopted. Our gas-phase chemistry is extracted from the UMIST Database for Astrochemistry (Rate06) to which we have added detailed gas-grain interactions. We use our chemical model results to generate synthetic near- and mid-infrared LTE line emission spectra and compare these with recent Spitzer observations. Our results show that if H2 formation on warm grains is taken into consideration, the H2O and OH abundances in the disk surface increase significantly. We find the radial accretion flow strongly influences the molecular abundances, with those in the cold midplane layers particularly affected. On the other hand, we show that diffusive turbulent mixing affects the disk chemistry in the warm molecular layers, influencing the line ...

  3. Solar Energetic Particle Access to Distant Longitudes via Turbulent Field-Line Meandering

    E-Print Network [OSTI]

    Laitinen, T; Effenberger, F; Dalla, S; Marsh, M S

    2015-01-01

    Current Solar Energetic Particle (SEP) propagation models describe the effects of IMF turbulence on SEPs as diffusion, using a Fokker-Planck (FP) equation. However, these models cannot explain the observed fast access of SEPs to regions widely separated in longitude within the heliosphere, across the average magnetic field, without use of unrealistically strong cross-field diffusion. Here, we show that accounting for the SEP propagation along field-lines that meander due to plasma turbulence provides an explanation for the wide SEP events. Using a model that includes the non-diffusive effects caused by field-line meandering, we reproduce the observed longitudinal extent of SEP peak fluxes characterised by a Gaussian profile with sigma=30-50 degrees, while current diffusion theory can only explain extents of 10 degrees with realistic diffusion coefficients. Our model also reproduces the timing of SEP arrival at distant longitudes, which cannot be explained using the diffusion model.

  4. Chaotic mean wind in turbulent thermal convection and long-term correlations in solar activity

    E-Print Network [OSTI]

    A. Bershadskii

    2009-12-25

    It is shown that correlation function of the mean wind velocity in a turbulent thermal convection (Rayleigh number $Ra \\sim 10^{11}$) exhibits exponential decay with a very long correlation time, while corresponding largest Lyapunov exponent is certainly positive. These results together with the reconstructed phase portrait indicate presence of a chaotic component in the examined mean wind. Telegraph approximation is also used to study relative contribution of the chaotic and stochastic components to the mean wind fluctuations and an equilibrium between these components has been studied. Since solar activity is based on the thermal convection processes, it is reasoned that the observed solar activity long-term correlations can be an imprint of the mean wind chaotic properties. In particular, correlation function of the daily sunspots number exhibits exponential decay with a very long correlation time and corresponding largest Lyapunov exponent is certainly positive, also relative contribution of the chaotic and stochastic components follows the same pattern as for the convection mean wind.

  5. Flow visualization using momentum and energy transport tubes and applications to turbulent flow in wind farms

    E-Print Network [OSTI]

    Meyers, Johan

    2012-01-01

    As a generalization of the mass-flux based classical stream-tube, the concept of momentum and energy transport tubes is discussed as a flow visualization tool. These transport tubes have the property, respectively, that no fluxes of momentum or energy exist over their respective tube mantles. As an example application using data from large-eddy simulation, such tubes are visualized for the mean-flow structure of turbulent flow in large wind farms, in fully developed wind-turbine-array boundary layers. The three-dimensional organization of energy transport tubes changes considerably when turbine spacings are varied, enabling the visualization of the path taken by the kinetic energy flux that is ultimately available at any given turbine within the array.

  6. Bi-Directional Energy Cascades and the Origin of Kinetic Alfv\\'enic and Whistler Turbulence in the Solar Wind

    E-Print Network [OSTI]

    Che, H; Viñas, A F

    2013-01-01

    The observed sub-proton scale turbulence spectrum in the solar wind raises the question of how that turbulence originates. Observations of keV energetic electrons during solar quite-time suggest them as possible source of free energy to drive the turbulence. Using particle-in-cell simulations, we explore how free energy in energetic electrons, released by an electron two-stream instability drives Weibel-like electromagnetic waves that excite wave-wave interactions. Consequently, both kinetic Alfv\\'enic and whistler waves are excited that evolve through inverse and forward magnetic energy cascades.

  7. ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE

    SciTech Connect (OSTI)

    Zaheer, S.; Yoon, P. H.

    2013-10-01

    A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the ? distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized ? distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvénic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index ?, where f{sub e} ? v {sup –?} is close to the average index observed during the quiet-time solar wind condition, i.e., ? ? O(6.5) whereas ?{sub average} ? 6.69, according to observation.

  8. The role of energy storage in accessing remote wind resources in the Midwest

    E-Print Network [OSTI]

    Jaramillo, Paulina

    The role of energy storage in accessing remote wind resources in the Midwest Julian Lamy n , Inês L of energy storage to replace transmission. We focus on a wind farm in North Dakota that must deliver power to Illinois. Energy storage capital costs must be less than $100/kW h. Transmission capital costs must

  9. Power law burst and inter-burst interval distributions in the solar wind: turbulence or dissipative SOC ?

    E-Print Network [OSTI]

    M. P. Freeman; N. W. Watkins; D. J. Riley

    2000-06-28

    We calculate for the first time the probability density functions (PDFs) P of burst energy e, duration T and inter-burst interval tau for a known turbulent system in nature. Bursts in the earth-sun component of the Poynting flux at 1 AU in the solar wind were measured using the MFI and SWE experiments on the NASA WIND spacecraft. We find P(e) and P(T) to be power laws, consistent with self-organised criticality (SOC). We find also a power law form for P(tau) that distinguishes this turbulent cascade from the exponential P(tau) of ideal SOC, but not from some other SOC-like sandpile models. We discuss the implications for the relation between SOC and turbulence.

  10. MHD turbulence model for global simulations of the solar wind and SEP acceleration

    SciTech Connect (OSTI)

    Sokolov, Igor V.; Roussev, Ilia I.

    2008-08-25

    The aim of the present work is to unify the various transport equations for turbulent waves that are used in different areas of space physics. We mostly focus on the magnetohydrodynamic (MHD) turbulence, in particular the Alfvenic turbulence.

  11. Wake Turbulence of Two NREL 5-MW Wind Turbines Immersed in a Neutral Atmospheric Boundary-Layer Flow

    E-Print Network [OSTI]

    Bashioum, Jessica L; Schmitz, Sven; Duque, Earl P N

    2013-01-01

    The fluid dynamics video considers an array of two NREL 5-MW turbines separated by seven rotor diameters in a neutral atmospheric boundary layer (ABL). The neutral atmospheric boundary-layer flow data were obtained from a precursor ABL simulation using a Large-Eddy Simulation (LES) framework within OpenFOAM. The mean wind speed at hub height is 8m/s, and the surface roughness is 0.2m. The actuator line method (ALM) is used to model the wind turbine blades by means of body forces added to the momentum equation. The fluid dynamics video shows the root and tip vortices emanating from the blades from various viewpoints. The vortices become unstable and break down into large-scale turbulent structures. As the wakes of the wind turbines advect further downstream, smaller-scale turbulence is generated. It is apparent that vortices generated by the blades of the downstream wind turbine break down faster due to increased turbulence levels generated by the wake of the upstream wind turbine.

  12. ON THE LOW-FREQUENCY BOUNDARY OF SUN-GENERATED MAGNETOHYDRODYNAMIC TURBULENCE IN THE SLOW SOLAR WIND

    SciTech Connect (OSTI)

    Shergelashvili, Bidzina M.; Fichtner, Horst

    2012-06-20

    New aspects of the slow solar wind turbulent heating and acceleration are investigated. A physical meaning of the lower boundary of the Alfven wave turbulent spectra in the solar atmosphere and the solar wind is studied and the significance of this natural parameter is demonstrated. Via an analytical and quantitative treatment of the problem we show that a truncation of the wave spectra from the lower frequency side, which is a consequence of the solar magnetic field structure and its cyclic changes, results in a significant reduction of the heat production and acceleration rates. An appropriate analysis is presented regarding the link of the considered problem with existing observational data and slow solar wind initiation scenarios.

  13. Time-Dependent Turbulent Heating of Open Flux Tubes in the Chromosphere, Corona, and Solar Wind

    E-Print Network [OSTI]

    Woolsey, Lauren N

    2015-01-01

    We investigate several key questions of plasma heating in open-field regions of the corona that connect to the solar wind. We present results for a model of Alfven-wave-driven turbulence for three typical open magnetic field structures: a polar coronal hole, an open flux tube neighboring an equatorial streamer, and an open flux tube near a strong-field active region. We compare time-steady, one-dimensional turbulent heating models (Cranmer et al., 2007) against fully time-dependent three-dimensional reduced-magnetohydrodynamics modeling of BRAID (van Ballegooijen et al., 2011). We find that the time-steady results agree well with time-averaged results from BRAID. The time-dependence allows us to investigate the variability of the magnetic fluctuations and of the heating in the corona. The high-frequency tail of the power spectrum of fluctuations forms a power law whose exponent varies with height, and we discuss the possible physical explanation for this behavior. The variability in the heating rate is bursty...

  14. Anisotropic MHD Turbulence in the Interstellar Medium and Solar Wind http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&i... 1 of 1 6/18/07 12:12 PM

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Anisotropic MHD Turbulence in the Interstellar Medium and Solar Wind http://scitation, pp. 433-438 SOLAR WIND TEN: Proceedings of the Tenth International Solar Wind Conference Full Text. Anisotropic MHD Turbulence in the Interstellar Medium and Solar Wind A. Bhattacharjee and C. S. Ng Center

  15. ENSEMBLE SIMULATIONS OF PROTON HEATING IN THE SOLAR WIND VIA TURBULENCE AND ION CYCLOTRON RESONANCE

    SciTech Connect (OSTI)

    Cranmer, Steven R.

    2014-07-01

    Protons in the solar corona and heliosphere exhibit anisotropic velocity distributions, violation of magnetic moment conservation, and a general lack of thermal equilibrium with the other particle species. There is no agreement about the identity of the physical processes that energize non-Maxwellian protons in the solar wind, but a traditional favorite has been the dissipation of ion cyclotron resonant Alfvén waves. This paper presents kinetic models of how ion cyclotron waves heat protons on their journey from the corona to interplanetary space. It also derives a wide range of new solutions for the relevant dispersion relations, marginal stability boundaries, and nonresonant velocity-space diffusion rates. A phenomenological model containing both cyclotron damping and turbulent cascade is constructed to explain the suppression of proton heating at low alpha-proton differential flow speeds. These effects are implemented in a large-scale model of proton thermal evolution from the corona to 1 AU. A Monte Carlo ensemble of realistic wind speeds, densities, magnetic field strengths, and heating rates produces a filled region of parameter space (in a plane described by the parallel plasma beta and the proton temperature anisotropy ratio) similar to what is measured. The high-beta edges of this filled region are governed by plasma instabilities and strong heating rates. The low-beta edges correspond to weaker proton heating and a range of relative contributions from cyclotron resonance. On balance, the models are consistent with other studies that find only a small fraction of the turbulent power spectrum needs to consist of ion cyclotron waves.

  16. arXiv:0710.0763v1[astro-ph]3Oct2007 Small scale energy cascade of the solar wind turbulence

    E-Print Network [OSTI]

    Alexandrova, Olga

    arXiv:0710.0763v1[astro-ph]3Oct2007 Small scale energy cascade of the solar wind turbulence O depends neither on the energy injection nor on the energy dissipation processes. In the solar wind/CNR, Ponte P. Bucci, Cubo 33B, 87036 Rende (CS), Italy ABSTRACT Magnetic fluctuations in the solar wind

  17. Low-Order Modelling of Blade-Induced Turbulence for RANS Actuator Disk Computations of Wind and Tidal Turbines

    E-Print Network [OSTI]

    Nishino, Takafumi

    2012-01-01

    Modelling of turbine blade-induced turbulence (BIT) is discussed within the framework of three-dimensional Reynolds-averaged Navier-Stokes (RANS) actuator disk computations. We first propose a generic (baseline) BIT model, which is applied only to the actuator disk surface, does not include any model coefficients (other than those used in the original RANS turbulence model) and is expected to be valid in the limiting case where BIT is fully isotropic and in energy equilibrium. The baseline model is then combined with correction functions applied to the region behind the disk to account for the effect of rotor tip vortices causing a mismatch of Reynolds shear stress between short- and long-time averaged flow fields. Results are compared with wake measurements of a two-bladed wind turbine model of Medici and Alfredsson [Wind Energy, Vol. 9, 2006, pp. 219-236] to demonstrate the capability of the new model.

  18. Application of a solar wind model driven by turbulence dissipation to a 2D magnetic field configuration

    SciTech Connect (OSTI)

    Lionello, Roberto; Downs, Cooper; Linker, Jon A.; Miki?, Zoran; Velli, Marco E-mail: cdowns@predsci.com E-mail: mikic@predsci.com

    2014-12-01

    Although it is widely accepted that photospheric motions provide the energy source and that the magnetic field must play a key role in the process, the detailed mechanisms responsible for heating the Sun's corona and accelerating the solar wind are still not fully understood. Cranmer et al. developed a sophisticated, one-dimensional (1D), time-steady model of the solar wind with turbulence dissipation. By varying the coronal magnetic field, they obtain, for a single choice of wave properties, a realistic range of slow and fast wind conditions with a sharp latitudinal transition between the two streams. Using a 1D, time-dependent model of the solar wind of Lionello et al., which incorporates turbulent dissipation of Alfvén waves to provide heating and acceleration of the plasma, we have explored a similar configuration, obtaining qualitatively equivalent results. However, our calculations suggest that the rapid transition between slow and fast wind suggested by this 1D model may be disrupted in multidimensional MHD simulations by the requirement of transverse force balance.

  19. Anisotropic MHD/EMHD Turbulence in the Solar Wind and the Inte... http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verb... 1 of 1 3/10/05 11:25 AM

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Anisotropic MHD/EMHD Turbulence in the Solar Wind and the Inte... http://www-0284 TI: Anisotropic MHD/EMHD Turbulence in the Solar Wind and the Interstellar Medium AU 03824 United States AB: The solar wind and the interstellar medium is permeated by large-scale magnetic

  20. MULTI-SPACECRAFT OBSERVATIONS OF LINEAR MODES AND SIDEBAND WAVES IN ION-SCALE SOLAR WIND TURBULENCE

    SciTech Connect (OSTI)

    Perschke, Christopher; Motschmann, Uwe; Narita, Yasuhito; Glassmeier, Karl-Heinz

    2014-10-01

    In the scenario of weak turbulence, energy is believed to be cascaded from smaller to larger wave numbers and frequencies due to weak wave-wave interactions. Based on its perturbative treatment one may regard plasma turbulence as a superposition of linear modes (or normal modes) and sideband waves (or nonlinear modes). In this study, we use magnetic field and plasma measurements of nine solar wind events obtained by the Cluster spacecraft and make extensive use of a high-resolution wave vector analysis method, the Multi-point Signal Resonator technique, to find frequencies and wave vectors of discrete modes on ion kinetic scales in the plasma rest frame. The primarily unstructured wave observations in the frequency-wave number diagram are classified into three distinct linear modes (proton Bernstein modes, helium-alpha Bernstein modes, and kinetic Alfvén waves) and the sideband waves by comparing with the dispersion relations derived theoretically from linear Vlasov theory using observational values of the plasma parameter beta and the propagation angle from the mean magnetic field. About 60% of the observed discrete modes can be explained by the linear modes, primarily as the proton Bernstein and the kinetic Alfvén waves, within the frequency uncertainties, while the rest of the population (about 40%) cannot be classified as linear modes due to the large deviation from dispersion relations. We conclude that both the linear modes and sideband wave components are needed to construct the wave picture of solar wind turbulence on ion-kinetic scales.

  1. Power and spectral index anisotropy of the entire inertial range of turbulence in the fast solar wind

    E-Print Network [OSTI]

    Wicks, R T; Chen, C H K; Schekochihin, A A

    2010-01-01

    We measure the power and spectral index anisotropy of high speed solar wind turbulence from scales larger than the outer scale down to the ion gyroscale, thus covering the entire inertial range. We show that the power and spectral indices at the outer scale of turbulence are approximately isotropic. The turbulent cascade causes the power anisotropy at smaller scales manifested by anisotropic scalings of the spectrum: close to k^{-5/3} across and k^{-2} along the local magnetic field, consistent with a critically balanced Alfvenic turbulence. By using data at different radial distances from the Sun, we show that the width of the inertial range does not change with heliocentric distance and explain this by calculating the radial dependence of the ratio of the outer scale to the ion gyroscale. At the smallest scales of the inertial range, close to the ion gyroscale, we find an enhancement of power parallel to the magnetic field direction coincident with a decrease in the perpendicular power. This is most likely ...

  2. THE VIOLATION OF THE TAYLOR HYPOTHESIS IN MEASUREMENTS OF SOLAR WIND TURBULENCE

    SciTech Connect (OSTI)

    Klein, K. G.; Howes, G. G.; TenBarge, J. M.

    2014-08-01

    Motivated by the upcoming Solar Orbiter and Solar Probe Plus missions, qualitative and quantitative predictions are made for the effects of the violation of the Taylor hypothesis on the magnetic energy frequency spectrum measured in the near-Sun environment. The synthetic spacecraft data method is used to predict observational signatures of the violation for critically balanced Alfvénic turbulence or parallel fast/whistler turbulence. The violation of the Taylor hypothesis can occur in the slow flow regime, leading to a shift of the entire spectrum to higher frequencies, or in the dispersive regime, in which the dissipation range spectrum flattens at high frequencies. It is found that Alfvénic turbulence will not significantly violate the Taylor hypothesis, but whistler turbulence will. The flattening of the frequency spectrum is therefore a key observational signature for fast/whistler turbulence.

  3. Plasma turbulence and kinetic instabilities at ion scales in the expanding solar wind

    E-Print Network [OSTI]

    Hellinger, Petr; Landi, Simone; Verdini, Andrea; Franci, Luca; Travnicek, Pavel M

    2015-01-01

    The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2-D) hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular to the simulation box, and we start with a spectrum of large-scale, linearly-polarized, random-phase Alfv\\'enic fluctuations which have energy equipartition between kinetic and magnetic fluctuations and vanishing correlation between the two fields. A turbulent cascade rapidly develops, magnetic field fluctuations exhibit a Kolmogorov-like power-law spectrum at large scales and a steeper spectrum at ion scales. The turbulent cascade leads to an overall anisotropic proton heating, protons are heated in the perpendicular direction, and, initially, also in the parallel direction. The imposed expansion leads to generation of a large parallel proton temperature anisotropy which is at later stages partly reduced by turbulence. The turbulent heating is not sufficient to overco...

  4. The Effect of Magnetic Turbulence Energy Spectral

    E-Print Network [OSTI]

    Ng, Chung-Sang

    The Effect of Magnetic Turbulence Energy Spectral Scaling on the Heating of the Solar Wind C. S. Ng), Kraichnan (1965) #12;Solar wind turbulence model The steady state solar wind turbulence model developed wind with uniform speed Vsw 1D (radial position r) Turbulence characterized by two fields

  5. Ion kinetic energy conservation and magnetic field strength constancy in multi-fluid solar wind Alfv\\'enic turbulence

    E-Print Network [OSTI]

    Matteini, L; Pantellini, F; Velli, M; Schwartz, S J

    2015-01-01

    We investigate properties of the plasma fluid motion in the large amplitude low frequency fluctuations of highly Alfv\\'enic fast solar wind. We show that protons locally conserve total kinetic energy when observed from an effective frame of reference comoving with the fluctuations. For typical properties of the fast wind, this frame can be reasonably identified by alpha particles, which, owing to their drift with respect to protons at about the Alfv\\'en speed along the magnetic field, do not partake in the fluid low frequency fluctuations. Using their velocity to transform proton velocity into the frame of Alfv\\'enic turbulence, we demonstrate that the resulting plasma motion is characterized by a constant absolute value of the velocity, zero electric fields, and aligned velocity and magnetic field vectors as expected for unidirectional Alfv\\'enic fluctuations in equilibrium. We propose that this constraint, via the correlation between velocity and magnetic field in Alfv\\'enic turbulence, is at the origin of ...

  6. Turbulent Character of Wind Energy Patrick Milan, Matthias Wachter, and Joachim Peinke

    E-Print Network [OSTI]

    Peinke, Joachim

    intermittent, peaked nature of wind power fed into the grid. Multifractal scaling is observed, as described and more wind turbines become integrated into our electric grids, a proper understanding cause a highly fluctuating electrical power feed into the grid. Such effects are the hallmark of high

  7. Turbulence-driven coronal heating and improvements to empirical forecasting of the solar wind

    SciTech Connect (OSTI)

    Woolsey, Lauren N.; Cranmer, Steven R.

    2014-06-01

    Forecasting models of the solar wind often rely on simple parameterizations of the magnetic field that ignore the effects of the full magnetic field geometry. In this paper, we present the results of two solar wind prediction models that consider the full magnetic field profile and include the effects of Alfvén waves on coronal heating and wind acceleration. The one-dimensional magnetohydrodynamic code ZEPHYR self-consistently finds solar wind solutions without the need for empirical heating functions. Another one-dimensional code, introduced in this paper (The Efficient Modified-Parker-Equation-Solving Tool, TEMPEST), can act as a smaller, stand-alone code for use in forecasting pipelines. TEMPEST is written in Python and will become a publicly available library of functions that is easy to adapt and expand. We discuss important relations between the magnetic field profile and properties of the solar wind that can be used to independently validate prediction models. ZEPHYR provides the foundation and calibration for TEMPEST, and ultimately we will use these models to predict observations and explain space weather created by the bulk solar wind. We are able to reproduce with both models the general anticorrelation seen in comparisons of observed wind speed at 1 AU and the flux tube expansion factor. There is significantly less spread than comparing the results of the two models than between ZEPHYR and a traditional flux tube expansion relation. We suggest that the new code, TEMPEST, will become a valuable tool in the forecasting of space weather.

  8. Solar wind turbulence at 0.72 AU and solar minimum

    E-Print Network [OSTI]

    Teodorescu, Eliza; Munteanu, Costel; Zhang, Tielong; Bruno, Roberto; Kovacs, Peter

    2015-01-01

    We investigate Venus Express (VEX) observations of magnetic field fluctuations performed systematically in the solar wind at 0.72 Astronomical Units (AU), between 2007 and 2009, during the deep minimum of the solar cycle 24. The Power Spectral Densities (PSD) of the magnetic field components have been computed for the time intervals that satisfy data integrity criteria and have been grouped according to the type of wind, fast and slow defined for speeds larger and respectively smaller than 450 km/s. The PSDs show higher levels of power for the fast than for the slow wind. The spectral slopes estimated for all PSDs in the frequency range 0.005-0.1 Hz exhibit a normal distribution. The average value of the trace of the spectral matrix is -1.60 for fast solar wind and -1.65 for slow wind. Compared to the corresponding average slopes at 1 AU, the PSDs are shallower at 0.72 AU for slow wind conditions suggesting a steepening of the solar wind spectra between Venus and Earth. No significant time variation trend is ...

  9. WIND ENERGY Wind Energ. (2014)

    E-Print Network [OSTI]

    2014-01-01

    , wind power has been expanding globally in recent years and it has become a dominant renewable energy the turbulent atmosphere and the wind turbine wake in order to optimize the design of the wind turbine as wellWIND ENERGY Wind Energ. (2014) Published online in Wiley Online Library (wileyonlinelibrary

  10. STATIONARITY IN SOLAR WIND FLOWS

    SciTech Connect (OSTI)

    Perri, S.; Balogh, A. E-mail: a.balogh@imperial.ac.u

    2010-05-01

    By using single-point measurements in space physics it is possible to study a phenomenon only as a function of time. This means that we cannot have direct access to information about spatial variations of a measured quantity. However, the investigation of the properties of turbulence and of related phenomena in the solar wind widely makes use of an approximation frequently adopted in hydrodynamics under certain conditions, the so-called Taylor hypothesis; indeed, the solar wind flow has a bulk velocity along the radial direction which is much higher than the velocity of a single turbulent eddy embedded in the main flow. This implies that the time of evolution of the turbulent features is longer than the transit time of the flow through the spacecraft position, so that the turbulent field can be considered frozen into the solar wind flow. This assumption allows one to easily associate time variations with spatial variations and stationarity to homogeneity. We have investigated, applying criteria for weak stationarity to Ulysses magnetic field data in different solar wind regimes, at which timescale and under which conditions the hypothesis of stationarity, and then of homogeneity, of turbulence in the solar wind is well justified. We extend the conclusions of previous studies by Matthaeus and Goldstein to different parameter ranges in the solar wind. We conclude that the stationarity assumption in the inertial range of turbulence on timescales of 10 minutes to 1 day is reasonably satisfied in fast and uniform solar wind flows, but that in mixed, interacting fast, and slow solar wind streams the assumption is frequently only marginally valid.

  11. Turbulence-Driven Coronal Heating and Improvements to Empirical Forecasting of the Solar Wind

    E-Print Network [OSTI]

    Woolsey, Lauren N

    2014-01-01

    Forecasting models of the solar wind often rely on simple parameterizations of the magnetic field that ignore the effects of the full magnetic field geometry. In this paper, we present the results of two solar wind prediction models that consider the full magnetic field profile and include the effects of Alfv\\'en waves on coronal heating and wind acceleration. The one-dimensional MHD code ZEPHYR self-consistently finds solar wind solutions without the need for empirical heating functions. Another 1D code, introduced in this paper (The Efficient Modified-Parker-Equation-Solving Tool, TEMPEST), can act as a smaller, stand-alone code for use in forecasting pipelines. TEMPEST is written in Python and will become a publicly available library of functions that is easy to adapt and expand. We discuss important relations between the magnetic field profile and properties of the solar wind that can be used to independently validate prediction models. ZEPHYR provides the foundation and calibration for TEMPEST, and ultim...

  12. VELOCITY-SHEAR-INDUCED MODE COUPLING IN THE SOLAR ATMOSPHERE AND SOLAR WIND: IMPLICATIONS FOR PLASMA HEATING AND MHD TURBULENCE

    SciTech Connect (OSTI)

    Hollweg, Joseph V.; Chandran, Benjamin D. G.; Kaghashvili, Edisher Kh. E-mail: ekaghash@aer.com

    2013-06-01

    We analytically consider how velocity shear in the corona and solar wind can cause an initial Alfven wave to drive up other propagating signals. The process is similar to the familiar coupling into other modes induced by non-WKB refraction in an inhomogeneous plasma, except here the refraction is a consequence of velocity shear. We limit our discussion to a low-beta plasma, and ignore couplings into signals resembling the slow mode. If the initial Alfven wave is propagating nearly parallel to the background magnetic field, then the induced signals are mainly a forward-going (i.e., propagating in the same sense as the original Alfven wave) fast mode, and a driven signal propagating like a forward-going Alfven wave but polarized like the fast mode; both signals are compressive and subject to damping by the Landau resonance. For an initial Alfven wave propagating obliquely with respect to the magnetic field, the induced signals are mainly forward- and backward-going fast modes, and a driven signal propagating like a forward-going Alfven wave but polarized like the fast mode; these signals are all compressive and subject to damping by the Landau resonance. A backward-going Alfven wave, thought to be important in the development of MHD turbulence, is also produced, but it is very weak. However, we suggest that for oblique propagation of the initial Alfven wave the induced fast-polarized signal propagating like a forward-going Alfven wave may interact coherently with the initial Alfven wave and distort it at a strong-turbulence-like rate.

  13. Great Plains Turbulence Environment: Its Origins, Impact, and Simulation

    SciTech Connect (OSTI)

    Kelley, N. D.; Jonkman, B. J.; Scott, G. N.

    2006-12-01

    This paper summarizes the known impacts of nocturnal turbulence on wind turbine performance and operations.

  14. Wind energy offers considerable promise

    E-Print Network [OSTI]

    Langendoen, Koen

    Wind energy offers considerable promise: the wind itself is free, wind power is clean, wind power is clean, and it is inexhaustible. In recent years, research on wind energy has accelerated that are offered are: Wind Physics · Atmospheric aerodynamics and turbulence · Wind farm aerodynamics Rotor Design

  15. The Effect of Magnetic Turbulence Energy Spectra and

    E-Print Network [OSTI]

    Ng, Chung-Sang

    The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the Solar Wind ADimensionless parameter: [Iroshnikov 1963, Kraichnan 1965] #12;Solar wind turbulence model The steady state solar wind turbulence model developed by [Matthaeus et al. 1994, 1996] and later developments: Steady

  16. Accessibility

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News Publications Traditional Knowledge KiosksAbout UsAboutWeb Policies » Accessibility

  17. Accessibility

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of raregovAboutRecovery Act Recovery ActARMAccelerators,Access to the

  18. PHYSICAL REVIEW E 91, 023101 (2015) Permutation entropy and statistical complexity analysis of turbulence in laboratory plasmas and the

    E-Print Network [OSTI]

    Brown, Michael R.

    2015-01-01

    of turbulence in laboratory plasmas and the solar wind P. J. Weck, D. A. Schaffner, and M. R. Brown Swarthmore) turbulence in the plasma wind tunnel of the Swarthmore Spheromak Experiment (SSX), drift-wave turbulence turbulent magnetic fluctuations of the solar wind taken from the Wind spacecraft. The entropy and complexity

  19. Dust Dynamics in Protoplanetary Disk Winds Driven by Magneto-Rotational Turbulence: A Mechanism for Floating Dust Grains with Characteristic Size

    E-Print Network [OSTI]

    Miyake, Tomoya; Inutsuka, Shu-ichiro

    2015-01-01

    We investigate the dynamics of dust grains with various sizes in protoplanetary disk winds driven by magnetorotational turbulence, by simulating the time evolution of the dust grain distribution in the vertical direction. Small dust grains, which are well coupled to the gas, are dragged upward with the upflowing gas, while large grains remain near the midplane of a disk. Intermediate--size grains float at several scale heights from the midplane in time-averated force balance between the downward gravity and the upward gas drag. For the minimum mass solar nebula at 1 AU, dust grains with size of 20 -- 40 $\\mu m$ float at 5-10 scale heights from the midplane. Considering the dependence on the distance from the central star, smaller-size grains remain only in an outer region of the disk, while larger-size grains are distributed in a broader region. This implies that the dust depletion is expected to take place in small-to-large and inside-out manners. We also discuss the implication of our result to the observat...

  20. Modelling and Measurements of Power Losses and Turbulence

    E-Print Network [OSTI]

    Pryor, Sara C.

    at Middelgrunden Offshore Wind Farm R. J. Barthelmie*, , S. T. Frandsen and M. N. Nielsen, Wind Energy Department and turbulence increase due to wind turbine wake interac- tions in large offshore wind farms is crucial interactions in large offshore wind farms is crucial to optimizing wind farm design. Power losses due

  1. Access Framework: Model Text (November 2011) An Act to Establish a Framework for Development of Offshore Wind Power

    E-Print Network [OSTI]

    Firestone, Jeremy

    of Offshore Wind Power Whereas, the offshore waters of [State] are ecologically and economically vital public, Whereas, offshore wind power provides utility-scale renewable energy at competitive costs, helps to meet consequences; and Whereas, offshore wind power, being a domestic source of energy enhances U.S. energy

  2. Modelling of offshore wind turbine wakes with the wind farm program FLaP

    E-Print Network [OSTI]

    Heinemann, Detlev

    Modelling of offshore wind turbine wakes with the wind farm program FLaP Bernhard Lange(1) , Hans from the Danish offshore wind farm Vindeby. Vertical wake profiles and mean turbulence intensities are not modelled satisfactorily. Keywords: Offshore, wind farm, wake model, Vindeby, turbulence intensity

  3. Effects of incoming surface wind conditions on the wake characteristics and dynamic wind loads acting on a wind turbine model

    E-Print Network [OSTI]

    Hu, Hui

    . In addition to measuring dynamic wind loads acting on the model turbine by using a force-moment sensor, a high in the incoming ABL wind with higher turbulence intensity levels. The turbulent kinetic energy and Reynolds stress://dx.doi.org/10.1063/1.4904375] I. INTRODUCTION Wind energy, as a renewable energy source, has been playing a

  4. Observations of the scale-dependent turbulence and evaluation of the flux-gradient relationship for sensible heat for a closed Douglas-Fir canopy in very weak wind conditions

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

    Vickers, D.; Thomas, C.

    2014-05-13

    Observations of the scale-dependent turbulent fluxes and variances above, within and beneath a tall closed Douglas-Fir canopy in very weak winds are examined. The daytime subcanopy vertical velocity spectra exhibit a double-peak structure with peaks at time scales of 0.8 s and 51.2 s. A double-peak structure is also observed in the daytime subcanopy heat flux cospectra. The daytime momentum flux cospectra inside the canopy and in the subcanopy are characterized by a relatively large cross-wind component, likely due to the extremely light and variable winds, such that the definition of a mean wind direction, and subsequent partitioning of themore »momentum flux into along- and cross-wind components, has little physical meaning. Positive values of both momentum flux components in the subcanopy contribute to upward transfer of momentum, consistent with the observed mean wind speed profile. In the canopy at night at the smallest resolved scales, we find relatively large momentum fluxes (compared to at larger scales), and increasing vertical velocity variance with decreasing time scale, consistent with very small eddies likely generated by wake shedding from the canopy elements that transport momentum but not heat. We find unusually large values of the velocity aspect ratio within the canopy, consistent with enhanced suppression of the horizontal wind components compared to the vertical by the canopy. The flux-gradient approach for sensible heat flux is found to be valid for the subcanopy and above-canopy layers when considered separately; however, single source approaches that ignore the canopy fail because they make the heat flux appear to be counter-gradient when in fact it is aligned with the local temperature gradient in both the subcanopy and above-canopy layers. Modeled sensible heat fluxes above dark warm closed canopies are likely underestimated using typical values of the Stanton number.« less

  5. Structural responses and power output of a wind turbine are strongly affected by the wind field acting on the wind turbine. Knowledge about the wind field and its

    E-Print Network [OSTI]

    Stanford University

    ABSTRACT Structural responses and power output of a wind turbine are strongly affected by the wind affect the power output and structural responses of a wind turbine. Wind field characteristics are conventionally described by time averaged features, such as mean wind speed, turbulence intensity and power

  6. Thanks to Energy Department Funding, Safer Access to Offshore...

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

    Thanks to Energy Department Funding, Safer Access to Offshore Wind Turbine Platforms is Demonstrated Thanks to Energy Department Funding, Safer Access to Offshore Wind Turbine...

  7. Energy Department Announces Funding to Access Higher Quality...

    Office of Environmental Management (EM)

    Energy Department Announces Funding to Access Higher Quality Wind Resources and Lower Costs Energy Department Announces Funding to Access Higher Quality Wind Resources and Lower...

  8. Magnetohydrodynamic turbulence: Observation and experimenta) M. R. Brown, D. A. Schaffner, and P. J. Weck

    E-Print Network [OSTI]

    Brown, Michael R.

    beyond magnetohydrodynamics of solar wind turbulence in two-dimensional hybrid simulations Phys. Plasmas); 10.1063/1.1687688 Magnetohydrodynamic turbulence in the solar wind Phys. Plasmas 6, 4154 (1999); 10 with an example taken from MHD fluctuations in the solar wind. A single dataset from the Wind satellite

  9. Low-altitude atmospheric turbulence around an airport 

    E-Print Network [OSTI]

    Cass, Stanley Dale

    1972-01-01

    speed and the average wind speed computed over an entire run (approximately 1 hr). iv Profiles of wind speed were approximately logarithmic, but profiles of turbulent energy showed a large increase in the wake of large obstructions. Spectra of wind... from u 30-sec averages 56 57 28 Spectra of accelerometer and wind data for same period 59 LIST OF SYMBOLS Symbol Definition Exchange coefficient for momentum Height Time Kinetic energy Average kinetic energy of turbulence u' + v'2 + w' (' 2...

  10. Access Framework: Model Text (November 2011) An Act to Establish a Framework for Development of Offshore Wind Power

    E-Print Network [OSTI]

    Firestone, Jeremy

    an adaptive management system of monitoring and evaluation; BE IT ENACTED... Prepared by Jeremy Firestone, Whereas, offshore wind power provides utility-scale renewable energy at competitive costs, helps to meet the increasing energy demand in U.S. coastal areas, provides a price-stable means of energy generation, and does

  11. MAST/GEOG 667: Wind Power Meteorology Fall 2013, 3 credit hours

    E-Print Network [OSTI]

    Firestone, Jeremy

    MAST/GEOG 667: Wind Power Meteorology Fall 2013, 3 credit hours 1 to understand onshore, offshore, and airborne wind power. Topics include: forces affecting winds; terrain and land-use effects; air turbulence; numerical modeling; wind power

  12. Stochastic modeling of lift and drag dynamics under turbulent conditions

    E-Print Network [OSTI]

    Peinke, Joachim

    Matthias Wächter Joachim Peinke ForWind - Center for Wind Energy Research University of Oldenburg, Germany measurement. The model is being developed with the aim to integrate it into a general wind energy converter dynamics, drag dynamics. 1 Introduction Wind energy converters (WECs) are permanently exposed to turbulent

  13. Assessment of turbulence by high-order statistics. Offshore example.

    E-Print Network [OSTI]

    Peinke, Joachim

    ForWind - Center for Wind Energy Research University of Oldenburg, Germany 1 Summary OffshoreAssessment of turbulence by high-order statistics. Offshore example. Allan Morales Joachim Peinke. Keywords: Offshore turbulence. Intermittency. Tur- bulence Intensity. Log-Normal distributions. 2 Data sets

  14. Observations of the scale-dependent turbulence and evaluation of the flux–gradient relationship for sensible heat for a closed Douglas-fir canopy in very weak wind conditions

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

    Vickers, D.; Thomas, C. K.

    2014-09-16

    Observations of the scale-dependent turbulent fluxes, variances, and the bulk transfer parameterization for sensible heat above, within, and beneath a tall closed Douglas-fir canopy in very weak winds are examined. The daytime sub-canopy vertical velocity spectra exhibit a double-peak structure with peaks at timescales of 0.8 s and 51.2 s. A double-peak structure is also observed in the daytime sub-canopy heat flux co-spectra. The daytime momentum flux co-spectra in the upper bole space and in the sub-canopy are characterized by a relatively large cross-wind component, likely due to the extremely light and variable winds, such that the definition of amore »mean wind direction, and subsequent partitioning of the momentum flux into along- and cross-wind components, has little physical meaning. Positive values of both momentum flux components in the sub-canopy contribute to upward transfer of momentum, consistent with the observed sub-canopy secondary wind speed maximum. For the smallest resolved scales in the canopy at nighttime, we find increasing vertical velocity variance with decreasing timescale, consistent with very small eddies possibly generated by wake shedding from the canopy elements that transport momentum, but not heat. Unusually large values of the velocity aspect ratio within the canopy were observed, consistent with enhanced suppression of the horizontal wind components compared to the vertical by the very dense canopy. The flux–gradient approach for sensible heat flux is found to be valid for the sub-canopy and above-canopy layers when considered separately in spite of the very small fluxes on the order of a few W m?2 in the sub-canopy. However, single-source approaches that ignore the canopy fail because they make the heat flux appear to be counter-gradient when in fact it is aligned with the local temperature gradient in both the sub-canopy and above-canopy layers. While sub-canopy Stanton numbers agreed well with values typically reported in the literature, our estimates for the above-canopy Stanton number were much larger, which likely leads to underestimated modeled sensible heat fluxes above dark warm closed canopies.« less

  15. Access Framework: Model Text (November 2011): An Act to Establish a Framework for Development of Offshore Wind Power

    SciTech Connect (OSTI)

    Jeremy Firestone; Dawn Kurtz Crompton

    2011-10-22

    The model offshore wind power legislation focused on two aspects: compensation for use of ocean space and environmental assessment. In particular, the model legislation recommends the adoption of a rent and royalty scheme that is premised on high rent and low royalties in order to stimulate qualified bids from developers who are motivated to begin production as early as possible and to discourage sham bidding. The model legislation also includes a provision that sets royalties at a lower rate in the early years of project operation, and that provides states with the discretion to waive or defer rent and/or royalties for a period of time to meet the goals and objectives of energy independence, job creation, reduced emissions of conventional pollutants and greenhouse gases and increased state requirements for electricity from renewable sources. The environmental impact assessment (EIA) is structured to provide a systematic and interdisciplinary evaluation of the potential positive and negative life-cycle effects of a proposed offshore wind project on the physical, biological, cultural and socio-economic attributes of the project.

  16. A Fatigue Approach to Wind Turbine Control

    E-Print Network [OSTI]

    A Fatigue Approach to Wind Turbine Control Keld Hammerum Kongens Lyngby 2006 #12;Technical to the turbulent nature of wind, the structural components of a wind turbine are exposed to highly varying loads. Therefore, fatigue damage is a major consideration when designing wind turbines. The control scheme applied

  17. LIDAR Wind Speed Measurements of Evolving Wind Fields

    SciTech Connect (OSTI)

    Simley, E.; Pao, L. Y.

    2012-07-01

    Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed Taylor's frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations to create a more realistic measurement model. A simple model of wind evolution is applied to a frozen wind field used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements are also evaluated with a large eddy simulation of a stable boundary layer provided by the National Center for Atmospheric Research. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios.

  18. The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the

    E-Print Network [OSTI]

    Ng, Chung-Sang

    The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the Solar Wind C, Durham, NH 03824, USA Abstract. In recent years, a phenomenological solar wind heating model based a shallower spectrum generates less waves and turbulence. Keywords: Pickup ions, Solar wind heating, MHD

  19. Reduced Models of Magnetohydrodynamic Turbulence in the Interstellar Medium and the

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Reduced Models of Magnetohydrodynamic Turbulence in the Interstellar Medium and the Solar Wind A and the solar wind. These equations apply to a plasma permeated by a spatially varying mean magnetic field when of turbulence in the interstellar medium (ISM) and the solar wind. There is strong observa- tional evidence

  20. Ris-R-1239(EN) Wind Energy Department

    E-Print Network [OSTI]

    Risø-R-1239(EN) Wind Energy Department: Scientific and Technical Progress 1999 - 2000 Birthe The activities of the Wind Energy Department fall within boundary layer meteorology, atmospheric turbulence of wind turbines; prediction of wind loads and wind resources as well as methods to determine

  1. Wind energy information guide

    SciTech Connect (OSTI)

    1996-04-01

    This book is divided into nine chapters. Chapters 1--8 provide background and annotated references on wind energy research, development, and commercialization. Chapter 9 lists additional sources of printed information and relevant organizations. Four indices provide alphabetical access to authors, organizations, computer models and design tools, and subjects. A list of abbreviations and acronyms is also included. Chapter topics include: introduction; economics of using wind energy; wind energy resources; wind turbine design, development, and testing; applications; environmental issues of wind power; institutional issues; and wind energy systems development.

  2. Wind Power

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

    Wind Power Bioenergy Power Systems Wind Power Wind Power Main Page Outreach Programs Image Gallery FAQs Links Software Hydro Power INL Home Wind Power Introduction The Wind Power...

  3. Lake-size dependency of wind shear and convection as controls on gas exchange

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    Lake-size dependency of wind shear and convection as controls on gas exchange Jordan S. Read,1 the relative contributions of wind shear (u*) and convection (w*) to turbulence in the surface mixed layer wind shear (u*/w*

  4. NREL Studies Wind Farm Aerodynamics to Improve Siting (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-04-01

    NREL researchers have used high-tech instruments and high-performance computing to understand atmospheric turbulence and turbine wake behavior in order to improve wind turbine design and siting within wind farms.

  5. Interpreting Power Anisotropy Measurements in Plasma Turbulence

    E-Print Network [OSTI]

    Chen, C H K; Horbury, T S; Schekochihin, A A

    2009-01-01

    A relationship between power anisotropy and wavevector anisotropy in turbulent fluctuations is derived. This can be used to interpret plasma turbulence measurements, for example in the solar wind. If fluctuations are anisotropic in shape then the ion gyroscale break point in spectra in the directions parallel and perpendicular to the magnetic field would not occur at the same frequency, and similarly for the electron gyroscale break point. This is an important consideration when interpreting solar wind observations in terms of anisotropic turbulence theories. Model magnetic field power spectra are presented assuming a cascade of critically balanced Alfven waves in the inertial range and kinetic Alfven waves in the dissipation range. The variation of power anisotropy with scale is compared to existing solar wind measurements and the similarities and differences are discussed.

  6. Optical Turbulence Characterization at LAMOST Site: Observations and Models

    E-Print Network [OSTI]

    Liu, L -Y; Yao, Y -Q; Vernin, J; Chadid, M; Wang, H -S; Yin, J; Wang, Y -P

    2015-01-01

    Atmospheric optical turbulence seriously limits the performance of high angular resolution instruments. An 8-night campaign of measurements was carried out at the LAMOST site in 2011, to characterize the optical turbulence. Two instruments were set up during the campaign: a Differential Image Motion Monitor (DIMM) used to measure the total atmospheric seeing, and a Single Star Scidar (SSS) to measure the vertical profiles of the turbulence C_n^2(h) and the horizontal wind velocity V(h). The optical turbulence parameters are also calculated with the Weather Research and Forecasting (WRF) model coupled with the Trinquet-Vernin model, which describes optical effects of atmospheric turbulence by using the local meteorological parameters. This paper presents assessment of the optical parameters involved in high angular resolution astronomy. Its includes seeing, isoplanatic angle, coherence time, coherence etendue, vertical profiles of optical turbulence intensity _n^2(h)$ and horizontal wind speed V(h). The median...

  7. Turbulent combustion

    SciTech Connect (OSTI)

    Talbot, L.; Cheng, R.K. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  8. Turbulence transport modeling of the temporal outer heliosphere

    SciTech Connect (OSTI)

    Adhikari, L.; Zank, G. P.; Hu, Q.; Dosch, A.

    2014-09-20

    The solar wind can be regarded as a turbulent magnetofluid, evolving in an expanding solar wind and subject to turbulent driving by a variety of in situ sources. Furthermore, the solar wind and the drivers of turbulence are highly time-dependent and change with solar cycle. Turbulence transport models describing low-frequency magnetic and velocity fluctuations in the solar wind have so far neglected solar cycle effects. Here we consider the effects of solar cycle variability on a turbulence transport model developed by Zank et al. This model is appropriate for the solar wind beyond about 1 AU, and extensions have described the steady-state dependence of the magnetic energy density fluctuations, correlation length, and solar wind temperature throughout the outer heliosphere. We find that the temporal solar wind introduces a periodic variability, particularly beyond ?10 AU, in the magnetic energy density fluctuations, correlation length, and solar wind temperature. The variability is insufficient to account for the full observed variability in these quantities, but we find that the time-dependent solutions trace the steady-state solutions quite well, suggesting that the steady-state models are reasonable first approximations.

  9. Passive Tomography of Turbulence Strength Marina Alterman1

    E-Print Network [OSTI]

    Schechner, Yoav Yosef

    industrial, rural and urban areas. 1 The Need to Recover Turbulence Strength Turbulence creates refractive. Hence, modeling and trying to compensate for random refractive distortions has long been studied), wind, and atmospheric stability. This is measured using special Doppler lidars [9, 31], which are very

  10. Wind resource assessment with a mesoscale non-hydrostatic model

    E-Print Network [OSTI]

    Boyer, Edmond

    Wind resource assessment with a mesoscale non- hydrostatic model Vincent Guénard, Center for Energy is developed for assessing the wind resource and its uncertainty. The work focuses on an existing wind farm mast measurements. The wind speed and turbulence fields are discussed. It is shown that the k

  11. Web Accessibility Accessibility

    E-Print Network [OSTI]

    Oklahoma, University of

    Web Accessibility #12;Accessibility Webaim This is a pre-y prolific site that vary based on the type of web content. StaFc, content managed and dynamic web sites can benefit from our accessibility review service. Rich media

  12. Numerical simulations of strong incompressible magnetohydrodynamic turbulence

    SciTech Connect (OSTI)

    Mason, J.; Cattaneo, F.; Perez, J. C.; Boldyrev, S.

    2012-05-15

    Magnetised plasma turbulence pervades the universe and is likely to play an important role in a variety of astrophysical settings. Magnetohydrodynamics (MHD) provides the simplest theoretical framework in which phenomenological models for the turbulent dynamics can be built. Numerical simulations of MHD turbulence are widely used to guide and test the theoretical predictions; however, simulating MHD turbulence and accurately measuring its scaling properties is far from straightforward. Computational power limits the calculations to moderate Reynolds numbers and often simplifying assumptions are made in order that a wider range of scales can be accessed. After describing the theoretical predictions and the numerical approaches that are often employed in studying strong incompressible MHD turbulence, we present the findings of a series of high-resolution direct numerical simulations. We discuss the effects that insufficiencies in the computational approach can have on the solution and its physical interpretation.

  13. CHAPTER ____ THE AIR-WATER INTERFACE: TURBULENCE

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    Transport processes at gas-liquid interfaces are of importance in a number of areas, such as for equipment be generated by heat losses that give rise to natural convective motions on the liquid side. In the second winds, the turbulence is not only due to shear, but also due to natural convection on the liquid side

  14. Sandia Energy - Turbulent Combustion

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

    Combustion Home Transportation Energy Predictive Simulation of Engines Reacting Flow Experiments Turbulent Combustion Turbulent CombustionAshley Otero2015-10-30T01:39:47+00...

  15. Wind Powering America Podcasts, Wind Powering America (WPA)

    SciTech Connect (OSTI)

    Not Available

    2012-04-01

    Wind Powering America and the National Association of Farm Broadcasters produce a series of radio interviews featuring experts discussing wind energy topics. The interviews are aimed at a rural stakeholder audience and are available as podcasts. On the Wind Powering America website, you can access past interviews on topics such as: Keys to Local Wind Energy Development Success, What to Know about Installing a Wind Energy System on Your Farm, and Wind Energy Development Can Revitalize Rural America. This postcard is a marketing piece that stakeholders can provide to interested parties; it will guide them to this online resource for podcast episodes.

  16. Rotationally sampled wind characteristics and correlations with MOD-OA wind turbine response

    SciTech Connect (OSTI)

    George, R.L.; Connell, J.R.

    1984-09-01

    This report presents results of a comprehensive wind and wind turbine measurement program: the Clayton, New Mexico, vertical plane array/MOD-OA project. In this experiment, the turbulent wind was measured for a large array of fixed anemometers located two blade diameters upwind of a 200-kW horizontal-axis wind turbine (HAWT). Simultaneously, key wind turbine response parameters were also measured. The first of two major objectives of this experiment was to determine the turbulent wind, rotationally sampled to emulate the motion of the wind turbine blade, for the range of different wind speeds and stability classes actually experienced by the wind turbine. The second major objective was to correlate this rotationally sampled wind with the wind turbine blade stress and power, in order to assess the usefulness of the wind measurements for wind turbine loads testing a prediction. Time series of rotationally sampled winds and wind turbine blade bending moments and power were converted to frequency spectra using Fourier transform techniques. These spectra were used as the basis for both qualitative and quantitative comparisons among the various cases. A quantitative comparison between the rotationally sampled wind input and blade bending response was made, using the Fourier spectra to estimate the blade transfer function. These transfer functions were then used to calculate an approximate damping coefficient for the MOD-OA fiberglass blade.

  17. Modeling wind forcing in phase resolving simulation of nonlinear wind waves

    E-Print Network [OSTI]

    Kalmikov, Alexander G

    2010-01-01

    Wind waves in the ocean are a product of complex interaction of turbulent air flow with gravity driven water surface. The coupling is strong and the waves are non-stationary, irregular and highly nonlinear, which restricts ...

  18. Effects of Changing Atmospheric Conditions on Wind Turbine Performance (Poster)

    SciTech Connect (OSTI)

    Clifton, A.

    2012-12-01

    Multi-megawatt, utility-scale wind turbines operate in turbulent and dynamic winds that impact turbine performance in ways that are gradually becoming better understood. This poster presents a study made using a turbulent flow field simulator (TurbSim) and a Turbine aeroelastic simulator (FAST) of the response of a generic 1.5 MW wind turbine to changing inflow. The turbine power output is found to be most sensitive to wind speed and turbulence intensity, but the relationship depends on the wind speed with respect to the turbine's rated wind speed. Shear is found to be poorly correlated to power. A machine learning method called 'regression trees' is used to create a simple model of turbine performance that could be used as part of the wind resource assessment process. This study has used simple flow fields and should be extended to more complex flows, and validated with field observations.

  19. Modeling of wind and radar for simulation in four-dimensional navigation environment

    E-Print Network [OSTI]

    Malherbe, Gerard Andre

    1976-01-01

    Disturbances affecting time control precision in four-dimension navigation are modeled. Several models of wind and turbulence from the ground to ten thousand feet are developed. A distinction is made between wind mean and ...

  20. Supercomputers Capture Turbulence in the Solar Wind

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar Fuel Production 1: Total systemsSuccess NSECCapture

  1. Computational aspects of astrophysical MHD and turbulence

    E-Print Network [OSTI]

    Axel Brandenburg

    2001-09-27

    The advantages of high-order finite difference scheme for astrophysical MHD and turbulence simulations are highlighted. A number of one-dimensional test cases are presented ranging from various shock tests to Parker-type wind solutions. Applications to magnetized accretion discs and their associated outflows are discussed. Particular emphasis is placed on the possibility of dynamo action in three-dimensional turbulent convection and shear flows, which is relevant to stars and astrophysical discs. The generation of large scale fields is discussed in terms of an inverse magnetic cascade and the consequences imposed by magnetic helicity conservation are reviewed with particular emphasis on the issue of alpha-quenching.

  2. Journal of Wind Engineering and Industrial Aerodynamics 96 (2008) 503523

    E-Print Network [OSTI]

    Manuel, Lance

    2008-01-01

    Journal of Wind Engineering and Industrial Aerodynamics 96 (2008) 503­523 On the propagation of uncertainty in inflow turbulence to wind turbine loads Korn Saranyasoontorn, Lance Manuelà Department of Civil or design of wind turbines in normal operating states, it is common to use well-established standard

  3. Multiscale Nature of the Dissipation Range in Gyrokinetic Simulations of Alfvnic Turbulence

    E-Print Network [OSTI]

    Hammett, Greg

    solar wind parameters at 1 AU, about 30% of the nonlinear energy transfer close to the electron a radial temperature profile of the solar wind which can only be explained by the presence of heating measurements of solar wind fluctuation properties, and accomplishing increasingly detailed turbulence

  4. Airborne Wind Turbine

    SciTech Connect (OSTI)

    2010-09-01

    Broad Funding Opportunity Announcement Project: Makani Power is developing an Airborne Wind Turbine (AWT) that eliminates 90% of the mass of a conventional wind turbine and accesses a stronger, more consistent wind at altitudes of near 1,000 feet. At these altitudes, 85% of the country can offer viable wind resources compared to only 15% accessible with current technology. Additionally, the Makani Power wing can be economically deployed in deep offshore waters, opening up a resource which is 4 times greater than the entire U.S. electrical generation capacity. Makani Power has demonstrated the core technology, including autonomous launch, land, and power generation with an 8 meter wingspan, 20 kW prototype. At commercial scale, Makani Power aims to develop a 600 kW, 28 meter wingspan product capable of delivering energy at an unsubsidized cost competitive with coal, the current benchmark for low-cost power.

  5. Wind Tunnel 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    The increased interest in the offshore wind resource in both industry and academic and the extension of the wind field where offshore wind turbine can be deployed has stimulated quite a number of offshore wind turbines concepts. This thesis presents...

  6. Simulation of winds as seen by a rotating vertical axis wind turbine blade

    SciTech Connect (OSTI)

    George, R.L.

    1984-02-01

    The objective of this report is to provide turbulent wind analyses relevant to the design and testing of Vertical Axis Wind Turbines (VAWT). A technique was developed for utilizing high-speed turbulence wind data from a line of seven anemometers at a single level to simulate the wind seen by a rotating VAWT blade. Twelve data cases, representing a range of wind speeds and stability classes, were selected from the large volume of data available from the Clayton, New Mexico, Vertical Plane Array (VPA) project. Simulations were run of the rotationally sampled wind speed relative to the earth, as well as the tangential and radial wind speeds, which are relative to the rotating wind turbine blade. Spectral analysis is used to compare and assess wind simulations from the different wind regimes, as well as from alternate wind measurement techniques. The variance in the wind speed at frequencies at or above the blade rotation rate is computed for all cases, and is used to quantitatively compare the VAWT simulations with Horizontal Axis Wind Turbine (HAWT) simulations. Qualitative comparisons are also made with direct wind measurements from a VAWT blade.

  7. A Stochastic DEVS Wind Turbine Component Model for Wind Farm Simulation

    E-Print Network [OSTI]

    Ding, Yu

    . Many wind farms are located in remote areas or offshore and are therefore, less accessible. FurtherA Stochastic DEVS Wind Turbine Component Model for Wind Farm Simulation Eduardo P´erez, Lewis 3131 TAMU, College Station, TX 77843, USA. eduardopr@tamu.edu and ntaimo@tamu.edu Keywords: Wind farm

  8. WIND ENERGY Wind Energ. (2014)

    E-Print Network [OSTI]

    Peinke, Joachim

    2014-01-01

    to generate in this way wind speed fluctuations with similar statistics as observed in nature. Forces wereWIND ENERGY Wind Energ. (2014) Published online in Wiley Online Library (wileyonlinelibrary wind inflow conditions M. R. Luhur, J. Peinke, J. Schneemann and M. Wächter ForWind-Center for Wind

  9. Turbulent flow in graphene

    E-Print Network [OSTI]

    Kumar S. Gupta; Siddhartha Sen

    2010-06-05

    We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.

  10. AIAA-2004-0502 A COMPARISON OF WIND TURBINE DESIGN LOADS IN DIFFERENT

    E-Print Network [OSTI]

    Manuel, Lance

    wind speed. For wind turbine generator systems, a similar reliability-based design format is employedAIAA-2004-0502 1 A COMPARISON OF WIND TURBINE DESIGN LOADS IN DIFFERENT ENVIRONMENTS USING INVERSE, Austin, TX 78712 ABSTRACT* The influence of turbulence conditions on the design loads for wind turbines

  11. Quantum Gravity and Turbulence

    E-Print Network [OSTI]

    Vishnu Jejjala; Djordje Minic; Y. Jack Ng; Chia-Hsiung Tze

    2010-05-18

    We apply recent advances in quantum gravity to the problem of turbulence. Adopting the AdS/CFT approach we propose a string theory of turbulence that explains the Kolmogorov scaling in 3+1 dimensions and the Kraichnan and Kolmogorov scalings in 2+1 dimensions. In the gravitational context, turbulence is intimately related to the properties of spacetime, or quantum, foam.

  12. Gyrokinetic turbulence: a nonlinear route to dissipation through phase space

    E-Print Network [OSTI]

    A. A. Schekochihin; S. C. Cowley; W. Dorland; G. W. Hammett; G. G. Howes; G. G. Plunk; E. Quataert; T. Tatsuno

    2008-11-04

    This paper describes a conceptual framework for understanding kinetic plasma turbulence as a generalized form of energy cascade in phase space. It is emphasized that conversion of turbulent energy into thermodynamic heat is only achievable in the presence of some (however small) degree of collisionality. The smallness of the collision rate is compensated by the emergence of small-scale structure in the velocity space. For gyrokinetic turbulence, a nonlinear perpendicular phase mixing mechanism is identified and described as a turbulent cascade of entropy fluctuations simultaneously occurring at spatial scales smaller than the ion gyroscale and in velocity space. Scaling relations for the resulting fluctuation spectra are derived. An estimate for the collisional cutoff is provided. The importance of adequately modeling and resolving collisions in gyrokinetic simulations is biefly discussed, as well as the relevance of these results to understanding the dissipation-range turbulence in the solar wind and the electrostatic microturbulence in fusion plasmas.

  13. IDENTIFYING CURRENT-SHEET–LIKE STRUCTURES IN THE SOLAR WIND

    E-Print Network [OSTI]

    Li, Gang

    2008-01-01

    Ulysses for two periods, one in solar maximum and the otherstructures in solar wind turbulence are one-dimensionalone can infer the existence of current sheets in the solar

  14. Experimental and theoretical study of horizontal-axis wind turbines

    E-Print Network [OSTI]

    Anderson, Michael Broughton

    1981-10-20

    An experimental and theoretical study of horizontal-axis wind turbines is undertaken. The theoretical analyses cover the four major areas of aerodynamics, turbulence. aeroelasticity and blade optimisation. EXisting aerodynamic theories based...

  15. Collegiate Wind Competition Wind Tunnel Specifications | Department...

    Energy Savers [EERE]

    Wind Tunnel Specifications Collegiate Wind Competition Wind Tunnel Specifications Collegiate Wind Competition Wind Tunnel Specifications Teams competing in the U.S. Department of...

  16. Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm

    SciTech Connect (OSTI)

    Wharton, S; Lundquist, J K

    2010-02-22

    Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow and turbulence at these heights in the boundary layer. Depending on whether the boundary layer is stable, neutral, or convective, the mean wind speed, direction, and turbulence properties may vary greatly across the tall turbine swept area (40 to 120 m AGL). This variability can cause tall turbines to produce difference amounts of power during time periods with identical hub height wind speeds. Using meteorological and power generation data from a West Coast North American wind farm over a one-year period, our study synthesizes standard wind park observations, such as wind speed from turbine nacelles and sparse meteorological tower observations, with high-resolution profiles of wind speed and turbulence from a remote sensing platform, to quantify the impact of atmospheric stability on power output. We first compare approaches to defining atmospheric stability. The standard, limited, wind farm operations enable the calculation only of a wind shear exponent ({alpha}) or turbulence intensity (I{sub U}) from cup anemometers, while the presence at this wind farm of a SODAR enables the direct observation of turbulent kinetic energy (TKE) throughout the turbine rotor disk. Additionally, a nearby research meteorological station provided observations of the Obukhov length, L, a direct measure of atmospheric stability. In general, the stability parameters {alpha}, I{sub U}, and TKE are in high agreement with the more physically-robust L, with TKE exhibiting the best agreement with L. Using these metrics, data periods are segregated by stability class to investigate power performance dependencies. Power output at this wind farm is highly correlated with atmospheric stability during the spring and summer months, while atmospheric stability exerts little impact on power output during the winter and autumn periods. During the spring and summer seasons, power output for a given wind speed was significantly higher during stable conditions and significantly lower during strongly convective conditions: power output differences approached 20% between stable and convective regimes. The dependency of stability on power output was apparent only when both turbulence and the shape of the wind speed profile were considered. Turbulence is one of the mechanisms by which atmospheric stability affects a turbine's power curve at this particular site, and measurements of turbulence can yield actionable insights into wind turbine behavior.

  17. Alfven wave collisions, the fundamental building block of plasma turbulence. IV. Laboratory experiment

    E-Print Network [OSTI]

    Carter, Troy

    cascade of energy from large to small scales.9 In order to gain insight into this fundamental buildingAlfven wave collisions, the fundamental building block of plasma turbulence. IV. Laboratory heating, acceleration of the solar wind, and heating of the interstellar medium. Turbulence

  18. wind energy

    National Nuclear Security Administration (NNSA)

    5%2A en Pantex to Become Wind Energy Research Center http:nnsa.energy.govfieldofficesnponpopressreleasespantex-become-wind-energy-research-center

  19. The use of real-time off-site observations as a methodology for increasing forecast skill in prediction of large wind power ramps one or more hours ahead of their impact on a wind plant.

    SciTech Connect (OSTI)

    Martin Wilde, Principal Investigator

    2012-12-31

    ABSTRACT Application of Real-Time Offsite Measurements in Improved Short-Term Wind Ramp Prediction Skill Improved forecasting performance immediately preceding wind ramp events is of preeminent concern to most wind energy companies, system operators, and balancing authorities. The value of near real-time hub height-level wind data and more general meteorological measurements to short-term wind power forecasting is well understood. For some sites, access to onsite measured wind data - even historical - can reduce forecast error in the short-range to medium-range horizons by as much as 50%. Unfortunately, valuable free-stream wind measurements at tall tower are not typically available at most wind plants, thereby forcing wind forecasters to rely upon wind measurements below hub height and/or turbine nacelle anemometry. Free-stream measurements can be appropriately scaled to hub-height levels, using existing empirically-derived relationships that account for surface roughness and turbulence. But there is large uncertainty in these relationships for a given time of day and state of the boundary layer. Alternatively, forecasts can rely entirely on turbine anemometry measurements, though such measurements are themselves subject to wake effects that are not stationary. The void in free-stream hub-height level measurements of wind can be filled by remote sensing (e.g., sodar, lidar, and radar). However, the expense of such equipment may not be sustainable. There is a growing market for traditional anemometry on tall tower networks, maintained by third parties to the forecasting process (i.e., independent of forecasters and the forecast users). This study examines the value of offsite tall-tower data from the WINDataNOW Technology network for short-horizon wind power predictions at a wind farm in northern Montana. The presentation shall describe successful physical and statistical techniques for its application and the practicality of its application in an operational setting. It shall be demonstrated that when used properly, the real-time offsite measurements materially improve wind ramp capture and prediction statistics, when compared to traditional wind forecasting techniques and to a simple persistence model.

  20. Journal of Turbulence, 2013 Vol. 14, No. 6, 3839, http://dx.doi.org/10.1080/14685248.2013.825725

    E-Print Network [OSTI]

    Dabiri, John O.

    .1080/14685248.2013.825725 ERRATUM Energy exchange in an array of vertical-axis wind turbines [Journal of Turbulence, Vol. 13, No. 38 2012) We analyze the flow field within an array of 18 counter-rotating, vertical-axis wind tur- bines a typical horizontal-axis wind turbine (HAWT). The observed high level of the planform kinetic energy flux

  1. Daytime turbulent exchange between the Amazon forest and the atmosphere

    SciTech Connect (OSTI)

    Fitzjarrald, D.R.; Moore, K.E. ); Cabral, M.R. ); Scolar, J. ); Manzi, A.O.; de Abreau Sa, L.D. )

    1990-09-20

    Detailed observations of turbulence just above and below the crown of the Amazon rain forest during the wet season are presented. The forest canopy is shown to remove high-frequency turbulent fluctuations while passing lower frequencies. Filter characteristics of turbulent transfer into the Amazon rain forest canopy are quantified. In spite of the ubiquitous presence of clouds and frequent rain during this season, the average horizontal wind speed spectrum and the relationship between the horizontal wind speed and its standard deviation are well described by dry convective boundary layer similarity hypotheses originally found to apply in flat terrain. Diurnal changes in the sign of the vertical velocity skewness observed above and inside the canopy are shown to be plausibly explained by considering the skewness budget. Simple empirical formulas that relate observed turbulent heat fluxes to horizontal wind speed and variance are presented. Changes in the amount of turbulent coupling between the forest and the boundary layer associated with deep convective clouds are presented in three case studies. Even small raining clouds are capable of evacuating the canopy of substances normally trapped by persistent static stability near the forest floor. Recovery from these events can take more than an hour, even during midday.

  2. ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS

    SciTech Connect (OSTI)

    Yoon, Peter H.; Kim, Sunjung; Lee, Junggi; Lee, Junhyun; Park, Jongsun; Park, Kyungsun; Seough, Jungjoon [School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Hong, Jinhy [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

    2012-08-20

    The present paper provides a possible explanation for the solar wind electron velocity distribution functions possessing asymmetric energetic tails. By numerically solving the electrostatic weak turbulence equations that involve nonlinear interactions among electrons, Langmuir waves, and ion-sound waves, it is shown that different ratios of ion-to-electron temperatures lead to the generation of varying degrees of asymmetric tails. The present finding may be applicable to observations in the solar wind near 1 AU and in other regions of the heliosphere and interplanetary space.

  3. Extracting Energy from Atmospheric Turbulence Chinmay K. Patel

    E-Print Network [OSTI]

    Stanford University

    ;2 thermal convection, birds also exploit the energy from wind shear and random gusts. Albatross, for example1 Extracting Energy from Atmospheric Turbulence Chinmay K. Patel Acuity Technologies Inc. Menlo@stanford.edu XXIX OSTIV Congress, Lüsse-Berlin, Germany, 6 August - 13 August 2008 Abstract Birds frequently use

  4. Toward Astrophysical Turbulence in the Laboratory G. G. Howes,1

    E-Print Network [OSTI]

    Carter, Troy

    is a ubiquitous phenomenon in space and astrophysical plasmas, driving a cascade of energy from large to small, the fundamental building block of astrophysical plasma turbulence. This measurement establishes a firm basis, playing a crucial role in the heating of the solar corona and accel- eration of the solar wind [1

  5. Formation of Jets by Baroclinic Turbulence BRIAN F. FARRELL

    E-Print Network [OSTI]

    Farrell, Brian F.

    Formation of Jets by Baroclinic Turbulence BRIAN F. FARRELL Department of Earth and Planetary spatial-scale jets; geophysical examples of this phenomenon include the Jovian banded winds and the earth's polar-front jet. These relatively steady large-scale jets arise from and are maintained by the smaller

  6. Fossil turbulence and fossil turbulence waves can be dangerous

    E-Print Network [OSTI]

    Carl H Gibson

    2012-11-25

    Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any other forces that tend to damp the eddies out. By this definition, turbulence always cascades from small scales where vorticity is created to larger scales where turbulence fossilizes. Fossil turbulence is any perturbation in a hydrophysical field produced by turbulence that persists after the fluid is no longer turbulent at the scale of the perturbation. Fossil turbulence patterns and fossil turbulence waves preserve and propagate energy and information about previous turbulence. Ignorance of fossil turbulence properties can be dangerous. Examples include the Osama bin Laden helicopter crash and the Air France 447 Airbus crash, both unfairly blamed on the pilots. Observations support the proposed definitions, and suggest even direct numerical simulations of turbulence require caution.

  7. Aero-Structural Design Investigations for Biplane Wind Turbine Blades

    E-Print Network [OSTI]

    Roth-Johnson, Perry

    2014-01-01

    of figures Land-based and offshore wind energy resource ofsamsung-s7.0-171, 2012. Accessed: [14] 4C Offshore, “Offshore Wind Turbine: S7.0-171, Sam- sung Heavy

  8. Passively cooled direct drive wind turbine

    DOE Patents [OSTI]

    Costin, Daniel P. (Chelsea, VT)

    2008-03-18

    A wind turbine is provided that passively cools an electrical generator. The wind turbine includes a plurality of fins arranged peripherally around a generator house. Each of the fins being oriented at an angle greater than zero degrees to allow parallel flow of air over the fin. The fin is further tapered to allow a constant portion of the fin to extend beyond the air stream boundary layer. Turbulence initiators on the nose cone further enhance heat transfer at the fins.

  9. Upstream Measurements of Wind Profiles with Doppler Lidar for Improved Wind Energy Integration

    SciTech Connect (OSTI)

    Rodney Frehlich

    2012-10-30

    New upstream measurements of wind profiles over the altitude range of wind turbines will be produced using a scanning Doppler lidar. These long range high quality measurements will provide improved wind power forecasts for wind energy integration into the power grid. The main goal of the project is to develop the optimal Doppler lidar operating parameters and data processing algorithms for improved wind energy integration by enhancing the wind power forecasts in the 30 to 60 minute time frame, especially for the large wind power ramps. Currently, there is very little upstream data at large wind farms, especially accurate wind profiles over the full height of the turbine blades. The potential of scanning Doppler lidar will be determined by rigorous computer modeling and evaluation of actual Doppler lidar data from the WindTracer system produced by Lockheed Martin Coherent Technologies, Inc. of Louisville, Colorado. Various data products will be investigated for input into numerical weather prediction models and statistically based nowcasting algorithms. Successful implementation of the proposed research will provide the required information for a full cost benefit analysis of the improved forecasts of wind power for energy integration as well as the added benefit of high quality wind and turbulence information for optimal control of the wind turbines at large wind farms.

  10. NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-11-01

    Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive-responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

  11. NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-10-01

    Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive -- responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

  12. Weakly Compressible and Anisotropic MHD Turbulence in the Sol... http://flux.aps.org/meetings/YR9596/BAPSDPP96/abs/S300032.html 1 of 1 3/10/05 11:15 AM

    E-Print Network [OSTI]

    Ng, Chung-Sang

    in the Solar Wind and the Interstellar Medium A. Bhattacharjee, C.S. Ng (The University of Iowa) Turbulent plasmas in the solar wind and the interstellar medium often contain a large directed magnetic field

  13. Reduced Models of MHD Turbulence: Implications for Density Fluct... http://flux.aps.org/meetings/YR99/DPP99/abs/S233006.html 1 of 1 3/10/05 10:34 AM

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Wind II. ORAL session, Monday afternoon, November 15 Fifth Avenue, The Westin Seattle [CM1.06] Reduced turbulence in the interstellar medium and the solar wind. These equations apply to a plasma permeated

  14. Spectral breaks of Alfvenic turbulence in a collisionless plasma

    E-Print Network [OSTI]

    Boldyrev, Stanislav; Xia, Qian; Zhdankin, Vladimir

    2015-01-01

    Recent observations reveal that magnetic turbulence in the nearly colisionless solar wind plasma extends to scales smaller than the plasma microscales, such as ion gyroradius and ion inertial length. Measured breaks in the spectra of magnetic and density fluctuations at high frequencies are thought to be related to the transition from large-scale hydromagnetic to small-scale kinetic turbulence. The scales of such transitions and the responsible physical mechanisms are not well understood however. In the present work we emphasize the crucial role of the plasma parameters in the transition to kinetic turbulence, such as the ion and electron plasma beta, the electron to ion temperature ratio, the degree of obliquity of turbulent fluctuations. We then propose an explanation for the spectral breaks reported in recent observations.

  15. Soliton Turbulence in Shallow Water Ocean Surface Waves

    E-Print Network [OSTI]

    Costa, Andrea; Resio, Donald T; Alessio, Silvia; Chrivì, Elisabetta; Saggese, Enrica; Bellomo, Katinka; Long, Chuck E

    2014-01-01

    We analyze shallow water wind waves in Currituck Sound, North Carolina and experimentally confirm, for the first time, the presence of $soliton$ $turbulence$ in ocean waves. Soliton turbulence is an exotic form of nonlinear wave motion where low frequency energy may also be viewed as a $dense$ $soliton$ $gas$, described theoretically by the soliton limit of the Korteweg-deVries (KdV) equation, a $completely$ $integrable$ $soliton$ $system$: Hence the phrase "soliton turbulence" is synonymous with "integrable soliton turbulence." For periodic/quasiperiodic boundary conditions the $ergodic$ $solutions$ of KdV are exactly solvable by $finite$ $gap$ $theory$ (FGT), the basis of our data analysis. We find that large amplitude measured wave trains near the energetic peak of a storm have low frequency power spectra that behave as $\\sim\\omega^{-1}$. We use the linear Fourier transform to estimate this power law from the power spectrum and to filter $densely$ $packed$ $soliton$ $wave$ $trains$ from the data. We apply ...

  16. INL Wind Farm Project Description Document

    SciTech Connect (OSTI)

    Gary Siefert

    2009-07-01

    The INL Wind Farm project proposes to install a 20 MW to 40 MW wind farm on government property, consisting of approximately ten to twenty full-sized (80-meter hub height) towers with 2 MW turbines, and access roads. This includes identifying the optimal turbine locations, building access roads, and pouring the tower foundations in preparation for turbine installation. The project successfully identified a location on INL lands with commercially viable wind resources (i.e., greater than 11 mph sustained winds) for a 20 to 40 MW wind farm. Additionally, the proposed Wind Farm was evaluated against other General Plant Projects, General Purpose Capital Equipment projects, and Line Item Construction Projects at the INL to show the relative importance of the proposed Wind Farm project.

  17. Model Ordinance for Siting of Wind-Energy Systems

    Broader source: Energy.gov [DOE]

    With respect to small wind turbines, the model ordinance addresses setbacks, access, lighting, noise, appearance, code compliance, utility notification, abandonment, and the permitting process....

  18. Penetrative turbulence associated with mesoscale surface heat flux variations

    E-Print Network [OSTI]

    Alam, Jahrul M

    2015-01-01

    This article investigates penetrative turbulence in the atmospheric boundary layer. Using a large eddy simulation approach, we study characteristics of the mixed layer with respect to surface heat flux variations in the range from 231.48 W/m$^2$ to 925.92 W/m$^2$, and observe that the surface heterogeneity on a spatial scale of $20$ km leads to downscale turbulent kinetic energy cascade. Coherent fluctuations of mesoscale horizontal wind is observed at 100m above the ground. Such a surface induced temporal oscillations in the horizontal wind suggest a rapid jump in mesocale wind forecasts, which is difficult to parameterize using traditional one-dimensional ensemble-mean models. Although the present work is idealized at a typical scale (20km) of surface heterogeneity, the results help develop effective subgrid scale parameterization schemes for classical weather forecasting mesoscale models.

  19. Refined critical balance in strong Alfvenic turbulence

    E-Print Network [OSTI]

    A. Mallet; A. A. Schekochihin; B. D. G. Chandran

    2015-08-24

    We present numerical evidence that in strong Alfvenic turbulence, the critical balance principle---equality of the nonlinear decorrelation and linear propagation times---is scale invariant, in the sense that the probability distribution of the ratio of these times is independent of scale. This result only holds if the local alignment of the Elsasser fields is taken into account in calculating the nonlinear time. At any given scale, the degree of alignment is found to increase with fluctuation amplitude, supporting the idea that the cause of alignment is mutual dynamical shearing of Elsasser fields. The scale-invariance of critical balance (while all other quantities of interest are strongly intermittent, i.e., have scale-dependent distributions) suggests that it is the most robust of the scaling principles used to describe Alfvenic turbulence. The quality afforded by situ fluctuation measurements in the solar wind allows for direct verification of this fundamental principle.

  20. A Note on the Estimation of Eddy Diffusivity and Dissipation Length in Low Winds

    E-Print Network [OSTI]

    Raman, Sethu

    poses a challenge for modeling air pollutant diffusion. In tropics, because of the dominant low wind atmosphere in low­wind speeds. Turbulence measurements at 1 Hz were made at 4-m level over an urban terrainA Note on the Estimation of Eddy Diffusivity and Dissipation Length in Low Winds over a Tropical

  1. Four Lectures on Turbulent Combustion

    E-Print Network [OSTI]

    Peters, Norbert

    Four Lectures on Turbulent Combustion N. Peters Institut f¨ur Technische Mechanik RWTH Aachen Turbulent Combustion: Introduction and Overview 1 1.1 Moment Methods in Modeling Turbulence with Combustion and Velocity Scales . . . . . . . . . . . 11 1.4 Regimes in Premixed Turbulent Combustion

  2. Wind Farm

    Broader source: Energy.gov [DOE]

    The wind farm in Greensburg, Kansas, was completed in spring 2010, and consists of ten 1.25 megawatt (MW) wind turbines that supply enough electricity to power every house, business, and municipal...

  3. Observations of Edge Turbulence

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

    Edge Turbulence near the X-point of Alcator C-Mod APS-2007 (1) J.L. Terry, S.J. Zweben*, B. LaBombard, I. Cziegler, O. Grulke + , D.P. Stotler* MIT - Plasma Science and Fusion...

  4. Wind Farm Recommendation Report

    SciTech Connect (OSTI)

    John Reisenauer

    2011-05-01

    On April 21, 2011, an Idaho National Laboratory (INL) Land Use Committee meeting was convened to develop a wind farm recommendation for the Executive Council and a list of proposed actions for proceeding with the recommendation. In terms of land use, the INL Land Use Committee unanimously agrees that Site 6 is the preferred location of the alternatives presented for an INL wind farm. However, further studies and resolution to questions raised (stated in this report) by the INL Land Use Committee are needed for the preferred location. Studies include, but are not limited to, wind viability (6 months), bats (2 years), and the visual impact of the wind farm. In addition, cultural resource surveys and consultation (1 month) and the National Environmental Policy Act process (9 to 12 months) need to be completed. Furthermore, there is no documented evidence of developers expressing interest in constructing a small wind farm on INL, nor a specific list of expectations or concessions for which a developer might expect INL to cover the cost. To date, INL assumes the National Environmental Policy Act activities will be paid for by the Department of Energy and INL (the environmental assessment has only received partial funding). However, other concessions also may be expected by developers such as roads, fencing, power line installation, tie-ins to substations, annual maintenance, snow removal, access control, down-time, and remediation. These types of concessions have not been documented, as a request, from a developer and INL has not identified the short and long-term cost liabilities for such concessions should a developer expect INL to cover these costs. INL has not identified a go-no-go funding level or the priority this Wind Farm Project might have with respect to other nuclear-related projects, should the wind farm remain an unfunded mandate. The Land Use Committee recommends Legal be consulted to determine what, if any, liabilities exist with the Wind Farm Project and INL’s rights and responsibilities in regards to access to the wind farm once constructed. An expression of interest is expected to go out soon to developers. However, with the potential of 2 years of study remaining for Site 6, the expectation of obtaining meaningful interest from developers should be questioned.

  5. Accessible buildings Moderately accessible buildings*

    E-Print Network [OSTI]

    Lee, Dongwon

    Campus neighborhood map Moderately accessible paths** Accessible building entrance via parking lot to the University Park campus. This map, provided by UAC, is designed to assist persons with disabilities in finding accessibility. Your observations and suggestions regarding architectural For more information on UAC, you can

  6. SCALING PROPERTIES OF SMALL-SCALE FLUCTUATIONS IN MAGNETOHYDRODYNAMIC TURBULENCE

    SciTech Connect (OSTI)

    Perez, Jean Carlos; Mason, Joanne; Boldyrev, Stanislav; Cattaneo, Fausto E-mail: j.mason@exeter.ac.uk E-mail: cattaneo@flash.uchicago.edu

    2014-09-20

    Magnetohydrodynamic (MHD) turbulence in the majority of natural systems, including the interstellar medium, the solar corona, and the solar wind, has Reynolds numbers far exceeding the Reynolds numbers achievable in numerical experiments. Much attention is therefore drawn to the universal scaling properties of small-scale fluctuations, which can be reliably measured in the simulations and then extrapolated to astrophysical scales. However, in contrast with hydrodynamic turbulence, where the universal structure of the inertial and dissipation intervals is described by the Kolmogorov self-similarity, the scaling for MHD turbulence cannot be established based solely on dimensional arguments due to the presence of an intrinsic velocity scale—the Alfvén velocity. In this Letter, we demonstrate that the Kolmogorov first self-similarity hypothesis cannot be formulated for MHD turbulence in the same way it is formulated for the hydrodynamic case. Besides profound consequences for the analytical consideration, this also imposes stringent conditions on numerical studies of MHD turbulence. In contrast with the hydrodynamic case, the discretization scale in numerical simulations of MHD turbulence should decrease faster than the dissipation scale, in order for the simulations to remain resolved as the Reynolds number increases.

  7. OBSERVATION OF FLUX-TUBE CROSSINGS IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Arnold, L.; Li, G.; Li, X.; Yan, Y.

    2013-03-20

    Current sheets are ubiquitous in the solar wind. They are a major source of the solar wind MHD turbulence intermittency. They may result from nonlinear interactions of the solar wind MHD turbulence or are the boundaries of flux tubes that originate from the solar surface. Some current sheets appear in pairs and are the boundaries of transient structures such as magnetic holes and reconnection exhausts or the edges of pulsed Alfven waves. For an individual current sheet, discerning whether it is a flux-tube boundary or due to nonlinear interactions or the boundary of a transient structure is difficult. In this work, using data from the Wind spacecraft, we identify two three-current-sheet events. Detailed examination of these two events suggests that they are best explained by the flux-tube-crossing scenario. Our study provides convincing evidence supporting the scenario that the solar wind consists of flux tubes where distinct plasmas reside.

  8. Wind Power Forecasting Data

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

    Operations Call 2012 Retrospective Reports 2012 Retrospective Reports 2011 Smart Grid Wind Integration Wind Integration Initiatives Wind Power Forecasting Wind Projects Email...

  9. Idaho_Wind_Data

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

    Site Bryans Run Cell Tower Site Wilson Peak Eckert Site Loertscher Boise State's Wind Data Link Wind Power Idaho Wind Data See also: Idaho Energy Resources - Wind, American...

  10. Turbine Inflow Characterization at the National Wind Technology Center: Preprint

    SciTech Connect (OSTI)

    Clifton, A.; Schreck, S.; Scott, G.; Kelley, N.; Lundquist, J.

    2012-01-01

    Utility-scale wind turbines operate in dynamic flows that can vary significantly over timescales from less than a second to several years. To better understand the inflow to utility-scale turbines, two inflow towers were installed and commissioned at the National Renewable Energy Laboratory's (NREL) National Wind Technology Center near Boulder, Colorado, in 2011. These towers are 135 m tall and instrumented with a combination of sonic anemometers, cup anemometers, wind vanes, and temperature measurements to characterize the inflow wind speed and direction, turbulence, stability and thermal stratification to two utility-scale turbines. Herein, we present variations in mean and turbulent wind parameters with height, atmospheric stability, and as a function of wind direction that could be important for turbine operation as well as persistence of turbine wakes. Wind speed, turbulence intensity, and dissipation are all factors that affect turbine performance. Our results shown that these all vary with height across the rotor disk, demonstrating the importance of measuring atmospheric conditions that influence wind turbine performance at multiple heights in the rotor disk, rather than relying on extrapolation from lower levels.

  11. Multidimensional turbulence spectra -identifying properties of turbulent structures

    E-Print Network [OSTI]

    Kevlahan, Nicholas

    Sweden 2 Department of Mathematics and Statistics, McMaster University, Hamilton L8S 4K1, Canada * E turbulent structures are presented. Results from analysis of the turbulent kinetic energy in turbulent energy associated with a coherent vortex defined using different vortex identification methods

  12. An integrated approach to offshore wind energy assessment: Great Lakes 3D Wind Experiment. Part I. Calibration and testing RJ Barthelmie1, SC Pryor1, CM Smith1, P Crippa1, H Wang1, R. Krishnamurthy2, R. Calhoun2, D Valyou3, P Marzocca3, D Matthiesen4, N.

    E-Print Network [OSTI]

    Polly, David

    An integrated approach to offshore wind energy assessment: Great Lakes 3D Wind Experiment. Part I Government or any agency thereof." Introduction An experiment to test wind and turbulence measurement strategies was conducted at a northern Indiana wind farm in May 2012. The experimental design focused

  13. 3D Pitot Tube Measurements and Calibration in the Wind Tunnel

    E-Print Network [OSTI]

    3D Pitot Tube Measurements and Calibration in the Wind Tunnel Center for Measurement Standards by CFD 9 #12;Copyright 2014 ITRI Omni-type 3D pitot tube Characterization of Pitot Tubes - Design of 3D.4) % · With grid No.4: T.I.= (1.7 to 4.4) % Grid-generated turbulent flow Calibration Facilities - Turbulence

  14. Quantum ghost imaging through turbulence

    E-Print Network [OSTI]

    Dixon, P. Ben

    We investigate the effect of turbulence on quantum ghost imaging. We use entangled photons and demonstrate that for a specific experimental configuration the effect of turbulence can be greatly diminished. By decoupling ...

  15. Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD

    SciTech Connect (OSTI)

    Wolfe, W.P. [Sandia National Labs., Albuquerque, NM (United States); Ochs, S.S. [Iowa State Univ., Ames, IA (United States). Aerospace Engineering Dept.

    1997-09-01

    An investigation was conducted into the capabilities and accuracy of a representative computational fluid dynamics code to predict the flow field and aerodynamic characteristics of typical wind-turbine airfoils. Comparisons of the computed pressure and aerodynamic coefficients were made with wind tunnel data. This work highlights two areas in CFD that require further investigation and development in order to enable accurate numerical simulations of flow about current generation wind-turbine airfoils: transition prediction and turbulence modeling. The results show that the laminar-to turbulent transition point must be modeled correctly to get accurate simulations for attached flow. Calculations also show that the standard turbulence model used in most commercial CFD codes, the k-e model, is not appropriate at angles of attack with flow separation. 14 refs., 28 figs., 4 tabs.

  16. MAGNETIC HELICITY IN THE DISSIPATION RANGE OF STRONG IMBALANCED TURBULENCE

    SciTech Connect (OSTI)

    Markovskii, S. A.; Vasquez, Bernard J. E-mail: bernie.vasquez@unh.edu

    2013-05-01

    Hybrid numerical simulations of freely decaying two-dimensional turbulence are presented. The background magnetic field is perpendicular to the simulation plane, which eliminates linear kinetic Alfven waves from the system. The net magnetic helicity of the initial fluctuations at large scales is zero. The turbulence is set to be imbalanced in the sense that the net cross-helicity is not zero. As the turbulence evolves, it develops nonzero magnetic helicity at smaller scales, in the proton kinetic range. In the quasi-steady state of evolution, the magnetic helicity spectrum has a peak consistent with the solar wind observations. The peak position depends on the plasma beta and correlates with a sharp decline of the cross-helicity spectrum.

  17. Bottleneck effect in three-dimensional turbulence simulations

    E-Print Network [OSTI]

    Wolfgang Dobler; Nils Erland L. Haugen; Tarek A. Yousef; Axel Brandenburg

    2003-08-27

    At numerical resolutions around $512^3$ and above, three-dimensional energy spectra from turbulence simulations begin to show noticeably shallower spectra than $k^{-5/3}$ near the dissipation wavenumber (`bottleneck effect'). This effect is shown to be significantly weaker in one-dimensional spectra such as those obtained in wind tunnel turbulence. The difference can be understood in terms of the transformation between one-dimensional and three-dimensional energy spectra under the assumption that the turbulent velocity field is isotropic. Transversal and longitudinal energy spectra are similar and can both accurately be computed from the full three-dimensional spectra. Second-order structure functions are less susceptible to the bottleneck effect and may be better suited for inferring the scaling exponent from numerical simulation data.

  18. Experimental Study of Free Stream Turbulence Effects on Dynamic Stall of Pitching Airfoil by using Particle Image Velocimetry

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    of attack histogram of a vertical axis wind turbine (VAWT). By using PIV, the instantaneous vortex, a great deal of attention has been paid to investigate the aerodynamic performance of vertical-axis wind turbines (VAWT) [4-6]. VAWT often operates inside an atmospheric turbulent boundary layer. The purpose

  19. Wind Tunnel 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    Simulation of Cooling Effect of Wind Tower on Passively Ventilated Building John Seryak Kelly Kissock Project Engineer Associate Professor Department of Mechanical and Aerospace Engineering University of Dayton... Dayton, Ohio ABSTRACT Traditional buildings are cooled and ventilated by mechanically induced drafts. Natural ventilation aspires to cool and ventilate a building by natural means, such as cross ventilation or wind towers, without mechanical...

  20. Inertial range scaling in numerical turbulence with hyperviscosity

    E-Print Network [OSTI]

    Nils Erland L. Haugen; Axel Brandenburg

    2004-10-26

    Numerical turbulence with hyperviscosity is studied and compared with direct simulations using ordinary viscosity and data from wind tunnel experiments. It is shown that the inertial range scaling is similar in all three cases. Furthermore, the bottleneck effect is approximately equally broad (about one order of magnitude) in these cases and only its height is increased in the hyperviscous case--presumably as a consequence of the steeper decent of the spectrum in the hyperviscous subrange. The mean normalized dissipation rate is found to be in agreement with both wind tunnel experiments and direct simulations. The structure function exponents agree with the She-Leveque model. Decaying turbulence with hyperviscosity still gives the usual t^{-1.25} decay law for the kinetic energy, and also the bottleneck effect is still present and about equally strong.

  1. Wave turbulent statistics in non-weak wave turbulence

    E-Print Network [OSTI]

    Naoto Yokoyama

    2011-05-08

    In wave turbulence, it has been believed that statistical properties are well described by the weak turbulence theory, in which nonlinear interactions among wavenumbers are assumed to be small. In the weak turbulence theory, separation of linear and nonlinear time scales derived from the weak nonlinearity is also assumed. However, the separation of the time scales is often violated even in weak turbulent systems where the nonlinear interactions are actually weak. To get rid of this inconsistency, closed equations are derived without assuming the separation of the time scales in accordance with Direct-Interaction Approximation (DIA), which has been successfully applied to Navier--Stokes turbulence. The kinetic equation of the weak turbulence theory is recovered from the DIA equations if the weak nonlinearity is assumed as an additional assumption. It suggests that the DIA equations is a natural extension of the conventional kinetic equation to not-necessarily-weak wave turbulence.

  2. Offshore Wind Power USA

    Broader source: Energy.gov [DOE]

    The Offshore Wind Power USA conference provides the latest offshore wind market updates and forecasts.

  3. Characterization of Relativistic MHD Turbulence

    E-Print Network [OSTI]

    Garrison, David

    2015-01-01

    The objective of this work is to understand if and how the characteristics of relativistic MHD turbulence may differ from those of nonrelativistic MHD turbulence. We accomplish this by studying the invariants in the relativistic case and comparing them to what we know of nonrelativistic turbulence. Although much work has been done to understand the dynamics of nonrelativistic systems (mostly for ideal incompressible fluids), there is minimal literature explicitly describing the dynamics of relativistic MHD turbulence. Many authors simply assume that relativistic turbulence has the same invariants and obeys the same inverse energy cascade as non-relativistic systems.

  4. Wind Energy Leasing Handbook

    E-Print Network [OSTI]

    Balasundaram, Balabhaskar "Baski"

    Wind Energy Leasing Handbook Wind Energy Leasing Handbook E-1033 Oklahoma Cooperative Extension?..................................................................................................................... 31 What do wind developers consider in locating wind energy projects?............................................................................................ 37 How do companies and individuals invest in wind energy projects?....................................................................

  5. Spatial confinement of the IBEX Ribbon: A dominant turbulence mechanism

    SciTech Connect (OSTI)

    Isenberg, Philip A.

    2014-05-20

    The narrow ribbon of enhanced energetic neutral atom flux observed by the Interstellar Boundary Explorer spacecraft has prompted numerous ideas to explain its structure and properties. One of these ideas is the 'neutral solar wind' scenario, which identifies the source particles as pickup protons in the local interstellar medium originating in solar wind charge-exchange interactions. This scenario has been thought to require unrealistically weak pitch-angle scattering of the pickup protons to explain the narrow structure. Recently, Schwadron and McComas suggested that this structure could result from a spatial retention of the pickup protons, rather than from a restricted pitch-angle distribution. Here, we present a physically motivated, quantitative mechanism to produce such a spatial configuration. This mechanism is based on the 'dominant turbulence' assumption, which can be applied where the production of new pickup protons is slow, and has been used to successfully explain the level of turbulent heating observed in the outer solar wind. This formalism predicts a pickup isotropization process which adds or subtracts energy from the ambient turbulent fluctuations, depending on the initial pitch angle of the pickup protons. We show that a simple model of this process can yield a ribbon structure in qualitative agreement with the observations. The results of this simple model are not yet quantitatively satisfactory, but we suggest several improvements which may reduce the quantitative discrepancy.

  6. Static magnetic fields enhance turbulence

    E-Print Network [OSTI]

    Pothérat, Alban

    2015-01-01

    More often than not, turbulence occurs under the influence of external fields, mostly rotation and magnetic fields generated either by planets, stellar objects or by an industrial environment. Their effect on the anisotropy and the dissipative behaviour of turbulence is recognised but complex, and it is still difficult to even tell whether they enhance or dampen turbulence. For example, externally imposed magnetic fields suppress free turbulence in electrically conducting fluids (Moffatt 1967), and make it two-dimensional (2D) (Sommeria & Moreau 1982); but their effect on the intensity of forced turbulence, as in pipes, convective flows or otherwise, is not clear. We shall prove that since two-dimensionalisation preferentially affects larger scales, these undergo much less dissipation and sustain intense turbulent fluctuations. When higher magnetic fields are imposed, quasi-2D structures retain more kinetic energy, so that rather than suppressing forced turbulence, external magnetic fields indirectly enha...

  7. Mesoscale and Large-Eddy Simulations for Wind Energy

    SciTech Connect (OSTI)

    Marjanovic, N

    2011-02-22

    Operational wind power forecasting, turbine micrositing, and turbine design require high-resolution simulations of atmospheric flow over complex terrain. The use of both Reynolds-Averaged Navier Stokes (RANS) and large-eddy (LES) simulations is explored for wind energy applications using the Weather Research and Forecasting (WRF) model. To adequately resolve terrain and turbulence in the atmospheric boundary layer, grid nesting is used to refine the grid from mesoscale to finer scales. This paper examines the performance of the grid nesting configuration, turbulence closures, and resolution (up to as fine as 100 m horizontal spacing) for simulations of synoptically and locally driven wind ramping events at a West Coast North American wind farm. Interestingly, little improvement is found when using higher resolution simulations or better resolved turbulence closures in comparison to observation data available for this particular site. This is true for week-long simulations as well, where finer resolution runs show only small changes in the distribution of wind speeds or turbulence intensities. It appears that the relatively simple topography of this site is adequately resolved by all model grids (even as coarse as 2.7 km) so that all resolutions are able to model the physics at similar accuracy. The accuracy of the results is shown in this paper to be more dependent on the parameterization of the land-surface characteristics such as soil moisture rather than on grid resolution.

  8. Modeling Sensitivities to the 20% Wind Scenario Report with the WinDS Model

    SciTech Connect (OSTI)

    Blair, N.; Hand, M.; Short, W.; Sullivan, P.

    2008-06-01

    In May 2008, DOE published '20% Wind Energy by 2030', a report which describes the costs and benefits of producing 20% of the nation's projected electricity demand in 2030 from wind technology. The total electricity system cost resulting from this scenario was modestly higher than a scenario in which no additional wind was installed after 2006. NREL's Wind Deployment System (WinDS) model was used to support this analysis. With its 358 regions, explicit treatment of transmission expansion, onshore siting considerations, shallow- and deep-water wind resources, 2030 outlook, explicit financing assumptions, endogenous learning, and stochastic treatment of wind resource variability, WinDS is unique in the level of detail it can bring to this analysis. For the 20% Wind Energy by 2030 analysis, the group chose various model structures (such as the ability to wheel power within an interconnect), and the wind industry agreed on a variety of model inputs (such as the cost of transmission or new wind turbines). For this paper, the analysis examined the sensitivity of the results to variations in those input values and model structure choices. These included wind cost and performance improvements over time, seasonal/diurnal wind resource variations, transmission access and costs, siting costs, conventional fuel cost trajectories, and conventional capital costs.

  9. THE EFFICIENCY OF SECOND-ORDER FERMI ACCELERATION BY WEAKLY COMPRESSIBLE MAGNETOHYDRODYNAMIC TURBULENCE

    SciTech Connect (OSTI)

    Lynn, Jacob W.; Quataert, Eliot; Parrish, Ian J.; Chandran, Benjamin D. G.

    2013-11-10

    We investigate the effects of pitch-angle scattering on the efficiency of particle heating and acceleration by MHD turbulence using phenomenological estimates and simulations of non-relativistic test particles interacting with strong, subsonic MHD turbulence. We include an imposed pitch-angle scattering rate, which is meant to approximate the effects of high-frequency plasma waves and/or velocity space instabilities. We focus on plasma parameters similar to those found in the near-Earth solar wind, though most of our results are more broadly applicable. An important control parameter is the size of the particle mean free path ?{sub mfp} relative to the scale of the turbulent fluctuations L. For small scattering rates, particles interact quasi-resonantly with turbulent fluctuations in magnetic field strength. Scattering increases the long-term efficiency of this resonant heating by factors of a few times 10, but the distribution function does not develop a significant non-thermal power-law tail. For higher scattering rates, the interaction between particles and turbulent fluctuations becomes non-resonant, governed by particles heating and cooling adiabatically as they encounter turbulent density fluctuations. Rapid pitch-angle scattering can produce a power-law tail in the proton distribution function, but this requires fine-tuning of parameters. Moreover, in the near-Earth solar wind, a significant power-law tail cannot develop by this mechanism because the particle acceleration timescales are longer than the adiabatic cooling timescale set by the expansion of the solar wind. Our results thus imply that MHD-scale turbulent fluctuations are unlikely to be the origin of the v {sup –5} tail in the proton distribution function observed in the solar wind.

  10. Aleutian Pribilof Islands Wind Energy Feasibility Study

    SciTech Connect (OSTI)

    Bruce A. Wright

    2012-03-27

    Under this project, the Aleutian Pribilof Islands Association (APIA) conducted wind feasibility studies for Adak, False Pass, Nikolski, Sand Point and St. George. The DOE funds were also be used to continue APIA's role as project coordinator, to expand the communication network quality between all participants and with other wind interest groups in the state and to provide continued education and training opportunities for regional participants. This DOE project began 09/01/2005. We completed the economic and technical feasibility studies for Adak. These were funded by the Alaska Energy Authority. Both wind and hydro appear to be viable renewable energy options for Adak. In False Pass the wind resource is generally good but the site has high turbulence. This would require special care with turbine selection and operations. False Pass may be more suitable for a tidal project. APIA is funded to complete a False Pass tidal feasibility study in 2012. Nikolski has superb potential for wind power development with Class 7 wind power density, moderate wind shear, bi-directional winds and low turbulence. APIA secured nearly $1M from the United States Department of Agriculture Rural Utilities Service Assistance to Rural Communities with Extremely High Energy Costs to install a 65kW wind turbine. The measured average power density and wind speed at Sand Point measured at 20m (66ft), are 424 W/m2 and 6.7 m/s (14.9 mph) respectively. Two 500kW Vestas turbines were installed and when fully integrated in 2012 are expected to provide a cost effective and clean source of electricity, reduce overall diesel fuel consumption estimated at 130,000 gallons/year and decrease air emissions associated with the consumption of diesel fuel. St. George Island has a Class 7 wind resource, which is superior for wind power development. The current strategy, led by Alaska Energy Authority, is to upgrade the St. George electrical distribution system and power plant. Avian studies in Nikolski and Sand Point have allowed for proper wind turbine siting without killing birds, especially endangered species and bald eagles. APIA continues coordinating and looking for funding opportunities for regional renewable energy projects. An important goal for APIA has been, and will continue to be, to involve community members with renewable energy projects and energy conservation efforts.

  11. Very-high-energy gamma radiation associated with the unshocked wind of the Crab pulsar

    E-Print Network [OSTI]

    S. V. Bogovalov; F. A. Aharonian

    2000-03-11

    We show that the relativistic wind in the Crab pulsar, which is commonly thought to be invisible in the region upstream of the termination shock at R wind that is not accessible at other wavelengths.

  12. U.S. Virgin Islands- Solar and Wind Easements & Rights Laws

    Broader source: Energy.gov [DOE]

    In the U.S. Virgin Islands, the owner of a solar or wind-energy system is permitted to negotiate for assurance of continued access to the system’s energy source. "Solar or wind-energy system" is...

  13. Polymer Stretching by Turbulence

    SciTech Connect (OSTI)

    Chertkov, Michael

    2000-05-15

    The stretching of a polymer chain by a large-scale chaotic flow is considered. The steady state which emerges as a balance of the turbulent stretching and anharmonic resistance of the chain is quantitatively described, i.e., the dependency on the flow parameters (Lyapunov exponent statistics) and the chain characteristics (the number of beads and the interbead elastic potential) is made explicit. (c) 2000 The American Physical Society.

  14. Few-Freedom Turbulence

    E-Print Network [OSTI]

    B. V. Chirikov; V. G. Davidovsky

    2000-06-15

    The results of numerical experiments on the structure of chaotic attractors in the Khalatnikov - Kroyter model of two freedoms are presented. This model was developed for a qualitative description of the wave turbulence of the second sound in helium. The attractor dimension, size, and the maximal Lyapunov exponent in dependence on the single dimensionless parameter $F$ of the model are found and discussed. The principal parameter $F$ is similar to the Reynolds number in hydrodynamic turbulence. We were able to discern four different attractors characterized by a specific critical value of the parameter ($F=F_{cr}$), such that the attractor exists for $F>F_{cr}$ only. A simple empirical relation for this dependence on the argument ($F-F_{cr}$) is presented which turns out to be universal for different attractors with respect to the dimension and dimensionless Lyapunov exponents. Yet, it differs as to the size of attractor. In the main region of our studies the dependence of all dimensionless characteristics of the chaotic attractor on parameter $F$ is very slow (logarithmic) which is qualitatively different as compared to that of a multi-freedom attractor, e.g., in hydrodynamic turbulence (a power law). However, at very large $F\\sim 10^7$ the transition to a power-law dependence has been finally found, similar to the multi-freedom attractor. Some unsolved problems and open questions are also discussed.

  15. Anisotropic MHD Turbulence in the Interstellar Medium and the Sol... http://www.aps.org/meet/DPP02/baps/abs/S120004.html 1 of 1 3/10/05 10:26 AM

    E-Print Network [OSTI]

    Ng, Chung-Sang

    -4, Rosen Centre Hotel [BI2.004] Anisotropic MHD Turbulence in the Interstellar Medium and the Solar Wind C of Iowa, 203 Van Allen Hall, Iowa City, Iowa 52242) The interstellar medium (ISM) and solar wind wind. Part B of program listing #12;

  16. Wind Vision: Impacts

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

    Wind Vision: Impacts Rich Tusing New West Technologies, LLC For EERE's Wind and Water Power Technologies Office July 15, 2015 2 | Wind and Water Power Technologies Office...

  17. Wind Program News

    SciTech Connect (OSTI)

    2012-01-06

    Stay current on the news about the wind side of the Wind and Water Power Program and important wind energy events around the U.S.

  18. Wind Power Link

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

    Wind Power Links These other web sites may provide additional information of interest: American Wind Energy Association Idaho Department of Energy Wind Power Information Utah...

  19. Energy 101: Wind Turbines

    ScienceCinema (OSTI)

    None

    2013-05-29

    See how wind turbines generate clean electricity from the power of the wind. Highlighted are the various parts and mechanisms of a modern wind turbine.

  20. Energy 101: Wind Turbines

    SciTech Connect (OSTI)

    None

    2011-01-01

    See how wind turbines generate clean electricity from the power of the wind. Highlighted are the various parts and mechanisms of a modern wind turbine.

  1. Vandenberg_Wind_Data

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

    Air Force and other branches of the Department of Defense for several years doing wind data collection and assessment, wind power feasibility studies, and wind farm design....

  2. Wind turbine having a direct-drive drivetrain

    DOE Patents [OSTI]

    Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

    2011-02-22

    A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  3. Wind turbine/generator set and method of making same

    DOE Patents [OSTI]

    Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

    2013-06-04

    A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  4. Eddy fluxes in baroclinic turbulence

    E-Print Network [OSTI]

    Thompson, Andrew F.

    2006-01-01

    cant dissipation of tidal energy in the deep ocean inferred2006: An estimate of tidal energy lost to turbulence at the

  5. Sandia Energy - Applied Turbulent Combustion

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

    and they form the basis for the creation of validated submodels that bridge fundamental energy sciences with applied device engineering and optimization. Turbulent-combustion-lab...

  6. Wind turbine

    DOE Patents [OSTI]

    Cheney, Jr., Marvin C. (Glastonbury, CT)

    1982-01-01

    A wind turbine of the type having an airfoil blade (15) mounted on a flexible beam (20) and a pitch governor (55) which selectively, torsionally twists the flexible beam in response to wind turbine speed thereby setting blade pitch, is provided with a limiter (85) which restricts unwanted pitch change at operating speeds due to torsional creep of the flexible beam. The limiter allows twisting of the beam by the governor under excessive wind velocity conditions to orient the blades in stall pitch positions, thereby preventing overspeed operation of the turbine. In the preferred embodiment, the pitch governor comprises a pendulum (65,70) which responds to changing rotor speed by pivotal movement, the limiter comprising a resilient member (90) which engages an end of the pendulum to restrict further movement thereof, and in turn restrict beam creep and unwanted blade pitch misadjustment.

  7. Impact of Increasing Distributed Wind Power and Wind Turbine Siting on Rural Distribution Feeder Voltage Profiles: Preprint

    SciTech Connect (OSTI)

    Allen, A.; Zhang, Y. C.; Hodge, B. M.

    2013-09-01

    Many favorable wind energy resources in North America are located in remote locations without direct access to the transmission grid. Building transmission lines to connect remotely-located wind power plants to large load centers has become a barrier to increasing wind power penetration in North America. By connecting utility-sized megawatt-scale wind turbines to the distribution system, wind power supplied to consumers could be increased greatly. However, the impact of including megawatt-scale wind turbines on distribution feeders needs to be studied. The work presented here examined the impact that siting and power output of megawatt-scale wind turbines have on distribution feeder voltage. This is the start of work to present a general guide to megawatt-scale wind turbine impact on the distribution feeder and finding the amount of wind power that can be added without adversely impacting the distribution feeder operation, reliability, and power quality.

  8. Wind Program: Wind Vision | Department of Energy

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

    Wind Vision: A New Era for Wind Power in the United States With more than 4.5% of the nation's electricity supplied by wind energy today, the Department of Energy has collaborated...

  9. Observation of the Dynamical Structure of Turbulence in Plasma Confined by a Dipole Magnetic Field

    E-Print Network [OSTI]

    Mauel, Michael E.

    improvements that allow observation of quasi-coherent structures and measurement of multipoint statistics-off-layers of toroidal fusion confinement devices[14­16], in the solar wind[17], in magnetized columns of electrons[18 the large-scale structure of turbulence consists of rotating, long-wavelength convective cells with ampli

  10. Direct Numerical Simulations of Interfacial Turbulence at Low Froude and Weber Numbers 

    E-Print Network [OSTI]

    Zhang, Qi

    2014-05-22

    that for this detection method the effects of ubiquitous surfactants (surface free agents) to the subsurface turbulence should also be considered. In the case when the wind stress at the surface is far less significant than the buoyancy force in the water phase, the cool...

  11. Turbulence-Turbine Interaction: The Basis for the Development of the TurbSim Stochastic Simulator

    SciTech Connect (OSTI)

    Kelley, N. D.

    2011-11-01

    A combination of taller wind turbines with more flexible rotors and towers operating in turbulent conditions that are not well understood is contributing to much higher than anticipated maintenance and repairs costs and is associated with lower energy production. This report documents evidence of this and offers the turbine designers an expanded tool that resolves many of these shortcomings.

  12. Alfven wave collisions, the fundamental building block of plasma turbulence. III. Theory for experimental design

    E-Print Network [OSTI]

    Carter, Troy

    Alfven wave collisions, the fundamental building block of plasma turbulence. III. Theory is a ubiquitous phenomenon in space and astrophysical plasmas, driving a cascade of energy from large to small, influencing the heating of the solar corona and acceleration of the solar wind,1 the dynamics

  13. Evaluation of three lidar scanning strategies for turbulence measurements

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

    Newman, J. F.; Klein, P. M.; Wharton, S.; Sathe, A.; Bonin, T. A.; Chilson, P. B.; Muschinski, A.

    2015-11-24

    Several errors occur when a traditional Doppler-beam swinging (DBS) or velocity–azimuth display (VAD) strategy is used to measure turbulence with a lidar. To mitigate some of these errors, a scanning strategy was recently developed which employs six beam positions to independently estimate the u, v, and w velocity variances and covariances. In order to assess the ability of these different scanning techniques to measure turbulence, a Halo scanning lidar, WindCube v2 pulsed lidar and ZephIR continuous wave lidar were deployed at field sites in Oklahoma and Colorado with collocated sonic anemometers. Results indicate that the six-beam strategy mitigates somemore »of the errors caused by VAD and DBS scans, but the strategy is strongly affected by errors in the variance measured at the different beam positions. The ZephIR and WindCube lidars overestimated horizontal variance values by over 60 % under unstable conditions as a result of variance contamination, where additional variance components contaminate the true value of the variance. A correction method was developed for the WindCube lidar that uses variance calculated from the vertical beam position to reduce variance contamination in the u and v variance components. The correction method reduced WindCube variance estimates by over 20 % at both the Oklahoma and Colorado sites under unstable conditions, when variance contamination is largest. This correction method can be easily applied to other lidars that contain a vertical beam position and is a promising method for accurately estimating turbulence with commercially available lidars.« less

  14. Evidence for internal structures of spiral turbulence

    E-Print Network [OSTI]

    2009-12-21

    Dec 22, 2009 ... ary laminar-turbulent pattern in plane Couette flow. ... flow internal to the turbulent and laminar spirals, and unique ... 2 ( is the fluid density).

  15. Simulation of lean premixed turbulent combustion

    E-Print Network [OSTI]

    2008-01-01

    turbulent methane combustion. Proc. Combust. Inst. , 29:in premixed turbulent combustion. Proc. Combust. Inst. ,for zero Mach number combustion. Combust. Sci. Technol. ,

  16. Wind | Department of Energy

    Office of Environmental Management (EM)

    Science & Innovation Energy Sources Renewable Energy Wind Wind Wind The United States is home to one of the largest and fastest growing wind markets in the world. To stay...

  17. Accessed Compositions in Turbulent Reactive Flows Stephen B. Pope

    E-Print Network [OSTI]

    , the thermochemical composition corresponds to a point in the multi-dimensional composition space. The union of all number flows, these compositions can be taken to be the specific moles of the ns species and the enthalpy, t) is sufficient to determine the elemental compo- sition of the mixture and the enthalpy (provided

  18. Wind Integration National Dataset (WIND) Toolkit

    Office of Energy Efficiency and Renewable Energy (EERE)

    For utility companies, grid operators and other stakeholders interested in wind energy integration, collecting large quantities of high quality data on wind energy resources is vitally important....

  19. Lake Michigan Offshore Wind Feasibility Assessment

    SciTech Connect (OSTI)

    Boezaart, Arnold; Edmonson, James; Standridge, Charles; Pervez, Nahid; Desai, Neel; Williams, Bruce; Clark, Aaron; Zeitler, David; Kendall, Scott; Biddanda, Bopi; Steinman, Alan; Klatt, Brian; Gehring, J. L.; Walter, K.; Nordman, Erik E.

    2014-06-30

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the project including to: 1) test and validate floating LIDAR technology; 2) collect and access offshore wind data; 3) detect and measure bird and bat activity over Lake Michigan; 4) conduct an over water sound propagation study; 5) prepare and offer a college course on offshore energy, and; 6) collect other environmental, bathometric, and atmospheric data. Desk-top research was performed to select anchorage sites and to secure permits to deploy the buoy. The project also collected and analyzed data essential to wind industry investment decision-making including: deploying highly mobile floating equipment to gather offshore wind data; correlating offshore wind data with conventional on-shore MET tower data; and performing studies that can contribute to the advancement and deployment of offshore wind technologies. Related activities included: • Siting, permitting, and deploying an offshore floating MET facility; • Validating the accuracy of floating LWS using near shoreline cup anemometer MET instruments; • Assessment of laser pulse technology (LIDAR) capability to establish hub height measurement of wind conditions at multiple locations on Lake Michigan; • Utilizing an extended-season (9-10 month) strategy to collect hub height wind data and weather conditions on Lake Michigan; • Investigation of technology best suited for wireless data transmission from distant offshore structures; • Conducting field-validated sound propagation study for a hypothetical offshore wind farm from shoreline locations; • Identifying the presence or absence of bird and bat species near wind assessment facilities; • Identifying the presence or absence of benthic and pelagic species near wind assessment facilities; All proposed project activities were completed with the following major findings: • Floating Laser Wind Sensors are capable of high quality measurement and recordings of wind resources. The WindSentinel presented no significant operational or statistical limitations in recording wind data technology at a at a high confidence level as compared to traditional an

  20. Matter & Energy Wind Energy

    E-Print Network [OSTI]

    Shepelyansky, Dima

    intuitive experience of a small wind not creating a storm, and that wind needs to reach a certain threshold

  1. Advances in compressible turbulent mixing

    SciTech Connect (OSTI)

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  2. Energy spectra in bubbly turbulence

    E-Print Network [OSTI]

    Prakash, Vivek N; Ramos, Fabio Ernesto Mancilla; Tagawa, Yoshiyuki; Lohse, Detlef; Sun, Chao

    2013-01-01

    We conduct experiments in a turbulent bubbly flow to study the unknown nature of the transition between the classical -5/3 energy spectrum scaling for a single-phase turbulent flow and the -3 scaling for a swarm of bubbles rising in a quiescent liquid and of bubble-dominated turbulence. The bubblance parameter, b, which measures the ratio of the bubble-induced kinetic energy to the kinetic energy induced by the turbulent liquid fluctuations before bubble injection, is used to characterise the bubbly flow. We vary b from $b = \\infty$ (pseudo-turbulence) to b = 0 (single-phase flow) over 2-3 orders of magnitude: ~O(0.01, 0.1, 5) to study its effect on the turbulent energy spectrum and liquid velocity fluctuations. The experiments are conducted in a multi-phase turbulent water tunnel with air bubbles of diameters 2-4 mm and 3-5 mm. An active-grid is used to generate nearly homogeneous and isotropic turbulence in the liquid flow. The liquid speeds and gas void fractions are varied to achieve the above mentioned b...

  3. Study of Nonlinear Interaction and Turbulence of Alfven Waves in LAPD Experiments

    SciTech Connect (OSTI)

    Boldyrev, Stanislav; Perez, Jean Carlos

    2013-11-29

    The complete project had two major goals — investigate MHD turbulence generated by counterpropagating Alfven modes, and study such processes in the LAPD device. In order to study MHD turbulence in numerical simulations, two codes have been used: full MHD, and reduced MHD developed specialy for this project. Quantitative numerical results are obtained through high-resolution simulations of strong MHD turbulence, performed through the 2010 DOE INCITE allocation. We addressed the questions of the spectrum of turbulence, its universality, and the value of the so-called Kolmogorov constant (the normalization coefficient of the spectrum). In these simulations we measured with unprecedented accuracy the energy spectra of magnetic and velocity fluctuations. We also studied the so-called residual energy, that is, the difference between kinetic and magnetic energies in turbulent fluctuations. In our analytic work we explained generation of residual energy in weak MHD turbulence, in the process of random collisions of counterpropagating Alfven waves. We then generalized these results for the case of strong MHD turbulence. The developed model explained generation of residual energy is strong MHD turbulence, and verified the results in numerical simulations. We then analyzed the imbalanced case, where more Alfven waves propagate in one direction. We found that spectral properties of the residual energy are similar for both balanced and imbalanced cases. We then compared strong MHD turbulence observed in the solar wind with turbulence generated in numerical simulations. Nonlinear interaction of Alfv´en waves has been studied in the upgraded Large Plasma Device (LAPD). We have simulated the collision of the Alfven modes in the settings close to the experiment. We have created a train of wave packets with the apltitudes closed to those observed n the experiment, and allowed them to collide. We then saw the generation of the second harmonic, resembling that observed in the experiment.

  4. GROWTH OF A LOCALIZED SEED MAGNETIC FIELD IN A TURBULENT MEDIUM

    SciTech Connect (OSTI)

    Cho, Jungyeon; Yoo, Hyunju

    2012-11-10

    Turbulence dynamo deals with the amplification of a seed magnetic field in a turbulent medium and has been studied mostly for uniform or spatially homogeneous seed magnetic fields. However, some astrophysical processes (e.g., jets from active galaxies, galactic winds, or ram-pressure stripping in galaxy clusters) can provide localized seed magnetic fields. In this paper, we numerically study amplification of localized seed magnetic fields in a turbulent medium. Throughout the paper, we assume that the driving scale of turbulence is comparable to the size of the system. Our findings are as follows. First, turbulence can amplify a localized seed magnetic field very efficiently. The growth rate of magnetic energy density is as high as that for a uniform seed magnetic field. This result implies that magnetic field ejected from an astrophysical object can be a viable source of a magnetic field in a cluster. Second, the localized seed magnetic field disperses and fills the whole system very fast. If turbulence in a system (e.g., a galaxy cluster or a filament) is driven at large scales, we expect that it takes a few large-eddy turnover times for the magnetic field to fill the whole system. Third, growth and turbulence diffusion of a localized seed magnetic field are also fast in high magnetic Prandtl number turbulence. Fourth, even in decaying turbulence, a localized seed magnetic field can ultimately fill the whole system. Although the dispersal rate of the magnetic field is not fast in purely decaying turbulence, it can be enhanced by an additional forcing.

  5. STATISTICS OF TURBULENT FIELD VARIATIONS, NON-GAUSSIANITY AND INTERMITTENCY

    SciTech Connect (OSTI)

    Ragot, B. R

    2009-05-10

    Statistics of magnetic field and velocity variations are important to the study of turbulence. Their departure from Gaussianity on the short separation scales has long been recognized and ascribed to intermittency. Non-Gaussian log-normal statistics of field-line separations are now predicted, however, from simple nonfluctuating turbulence Fourier spectra that do not model any intermittency, and one may wonder how this result may impact our interpretation of the statistics of field variations. It is shown in this paper how the intermittency of the turbulence can be taken into account to estimate the distributions of field-line separations and of field variations from the simple Fourier-spectra calculations. The first accurate theory/modeling predictions for the observed in situ distributions of turbulent field variations are thereby made, free of parameter adjustment. Magnetic field data from Helios 2 and Wind are used for the validation. Because the field variations are measured between points of constant separation and not between real field lines, intermittency remains the main cause for the observed non-Gaussianity of the statistics of field variations on the short scales, even if spatial limitations and/or short-scale phase correlations could also contribute to the deviations from Gaussianity.

  6. Wind Power: How Much, How Soon, and At What Cost?

    SciTech Connect (OSTI)

    Wiser, Ryan H; Hand, Maureen

    2010-01-01

    The global wind power market has been growing at a phenomenal pace, driven by favorable policies towards renewable energy and the improving economics of wind projects. On a going forward basis, utility-scale wind power offers the potential for significant reductions in the carbon footprint of the electricity sector. Specifically, the global wind resource is vast and, though accessing this potential is not costless or lacking in barriers, wind power can be developed at scale in the near to medium term at what promises to be an acceptable cost.

  7. The turbulent/non-turbulent interface at the outer boundary of a self-similar turbulent jet

    E-Print Network [OSTI]

    Hunt, Julian

    The turbulent/non-turbulent interface at the outer boundary of a self-similar turbulent jet J-similar turbulent jet at Re=2·103 is investigated ex- perimentally by means of combined particle image velo- cimetry (PIV) laser-induced fluorescence (LIF) measurements. The jet fluid contains a fluorescent dye so

  8. Stochastic modeling and performance monitoring of wind farm power production

    E-Print Network [OSTI]

    Milan, Patrick; Peinke, Joachim

    2015-01-01

    We present a new stochastic approach to describe and remodel the conversion process of a wind farm at a sampling frequency of 1Hz. When conditioning on various wind direction sectors, the dynamics of the conversion process appear as a fluctuating trajectory around an average IEC-like power curve, see section II. Our approach is to consider the wind farm as a dynamical system that can be described as a stochastic drift/diffusion model, where a drift coefficient describes the attraction towards the power curve and a diffusion coefficient quantifies additional turbulent fluctuations. These stochastic coefficients are inserted into a Langevin equation that, once properly adapted to our particular system, models a synthetic signal of power output for any given wind speed/direction signals, see section III. When combined with a pre-model for turbulent wind fluctuations, the stochastic approach models the power output of the wind farm at a sampling frequency of 1Hz using only ten-minute average values of wind speed ...

  9. Description of the Columbia Basin Wind Energy Study (CBWES)

    SciTech Connect (OSTI)

    Berg, Larry K.; Pekour, Mikhail S.; Nelson, Danny A.

    2012-10-01

    The purpose of this Technical Report is to provide background information about the Columbia Basin Wind Energy Study (CBWES). This study, which was supported by the U.S. Department of Energy’s Wind and Water Power Program, was conducted from 16 November 2010 through 21 March 2012 at a field site in northeastern Oregon. The primary goal of the study was to provide profiles of wind speed and wind direction over the depth of the boundary layer in an operating wind farm located in an area of complex terrain. Measurements from propeller and vane anemometers mounted on a 62 m tall tower, Doppler Sodar, and Radar Wind Profiler were combined into a single data product to provide the best estimate of the winds above the site during the first part of CBWES. An additional goal of the study was to provide measurements of Turbulence Kinetic Energy (TKE) near the surface. To address this specific goal, sonic anemometers were mounted at two heights on the 62 m tower on 23 April 2011. Prior to the deployment of the sonic anemometers on the tall tower, a single sonic anemometer was deployed on a short tower 3.1 m tall that was located just to the south of the radar wind profiler. Data from the radar wind profiler, as well as the wind profile data product are available from the Atmospheric Radiation Measurements (ARM) Data Archive (http://www.arm.gov/data/campaigns). Data from the sonic anemometers are available from the authors.

  10. Accessing PDSF

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News Publications Traditional Knowledge KiosksAbout UsAboutWeb Policies »FacilitiesAccessing

  11. Accessibility | NREL

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of raregovAboutRecovery Act Recovery ActARMAccelerators,Access toServices

  12. Gate Access

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeatureCleanperformanceCareersGate Access Gate

  13. Remote Access

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) by Carbon-RichProtonAbout UsRegionalScientific andRemote Access Remote

  14. Wind Technologies & Evolving Opportunities (Presentation)

    SciTech Connect (OSTI)

    Robichaud, R.

    2014-07-01

    This presentation covers opportunities for wind technology; wind energy market trends; an overview of the National Wind Technology Center near Boulder, Colorado; wind energy price and cost trends; wind turbine technology improvements; and wind resource characterization improvements.

  15. Memory effects in turbulent transport

    E-Print Network [OSTI]

    Alexander Hubbard; Axel Brandenburg

    2009-11-13

    In the mean-field theory of magnetic fields, turbulent transport, i.e. the turbulent electromotive force, is described by a combination of the alpha effect and turbulent magnetic diffusion, which are usually assumed to be proportional respectively to the mean field and its spatial derivatives. For a passive scalar there is just turbulent diffusion, where the mean flux of concentration depends on the gradient of the mean concentration. However, these proportionalities are approximations that are valid only if the mean field or the mean concentration vary slowly in time. Examples are presented where turbulent transport possesses memory, i.e. where it depends crucially on the past history of the mean field. Such effects are captured by replacing turbulent transport coefficients with time integral kernels, resulting in transport coefficients that depend effectively on the frequency or the growth rate of the mean field itself. In this paper we perform numerical experiments to find the characteristic timescale (or memory length) of this effect as well as simple analytical models of the integral kernels in the case of passive scalar concentrations and kinematic dynamos. The integral kernels can then be used to find self-consistent growth or decay rates of the mean fields. In mean-field dynamos the growth rates and cycle periods based on steady state values of alpha effect and turbulent diffusivity can be quite different from the actual values.

  16. Sandia Energy - Grid System Planning for Wind: Wind Generator...

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

    Grid System Planning for Wind: Wind Generator Modeling Home Stationary Power Energy Conversion Efficiency Wind Energy Siting and Barrier Mitigation Grid System Planning for Wind:...

  17. 2015 Iowa Wind Power Conference and Iowa Wind Energy Association...

    Office of Environmental Management (EM)

    2015 Iowa Wind Power Conference and Iowa Wind Energy Association Midwest Regional Energy Job Fair 2015 Iowa Wind Power Conference and Iowa Wind Energy Association Midwest Regional...

  18. Wind tunnel performance data for the Darrieus wind turbine with...

    Office of Scientific and Technical Information (OSTI)

    Wind tunnel performance data for the Darrieus wind turbine with NACA 0012 blades Citation Details In-Document Search Title: Wind tunnel performance data for the Darrieus wind...

  19. A National Offshore Wind Strategy: Creating an Offshore Wind...

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

    A National Offshore Wind Strategy: Creating an Offshore Wind Energy Industry in the United States A National Offshore Wind Strategy: Creating an Offshore Wind Energy Industry in...

  20. 20% Wind Energy by 2030 - Chapter 2: Wind Turbine Technology...

    Office of Environmental Management (EM)

    - Chapter 2: Wind Turbine Technology Summary Slides 20% Wind Energy by 2030 - Chapter 2: Wind Turbine Technology Summary Slides Summary slides for wind turbine technology, its...

  1. INTERCHANGE RECONNECTION IN A TURBULENT CORONA

    SciTech Connect (OSTI)

    Rappazzo, A. F.; Matthaeus, W. H. [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Ruffolo, D. [Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Servidio, S. [Dipartimento di Fisica, Universita della Calabria, I-87036 Cosenza (Italy); Velli, M., E-mail: rappazzo@udel.edu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-10-10

    Magnetic reconnection at the interface between coronal holes and loops, the so-called interchange reconnection, can release the hotter, denser plasma from magnetically confined regions into the heliosphere, contributing to the formation of the highly variable slow solar wind. The interchange process is often thought to develop at the apex of streamers or pseudo-streamers, near Y- and X-type neutral points, but slow streams with loop composition have been recently observed along fanlike open field lines adjacent to closed regions, far from the apex. However, coronal heating models, with magnetic field lines shuffled by convective motions, show that reconnection can occur continuously in unipolar magnetic field regions with no neutral points: photospheric motions induce a magnetohydrodynamic turbulent cascade in the coronal field that creates the necessary small scales, where a sheared magnetic field component orthogonal to the strong axial field is created locally and can reconnect. We propose that a similar mechanism operates near and around boundaries between open and closed regions inducing a continual stochastic rearrangement of connectivity. We examine a reduced magnetohydrodynamic model of a simplified interface region between open and closed corona threaded by a strong unipolar magnetic field. This boundary is not stationary, becomes fractal, and field lines change connectivity continuously, becoming alternatively open and closed. This model suggests that slow wind may originate everywhere along loop-coronal-hole boundary regions and can account naturally and simply for outflows at and adjacent to such boundaries and for the observed diffusion of slow wind around the heliospheric current sheet.

  2. Compound cooling flow turbulator for turbine component

    DOE Patents [OSTI]

    Lee, Ching-Pang; Jiang, Nan; Marra, John J; Rudolph, Ronald J

    2014-11-25

    Multi-scale turbulation features, including first turbulators (46, 48) on a cooling surface (44), and smaller turbulators (52, 54, 58, 62) on the first turbulators. The first turbulators may be formed between larger turbulators (50). The first turbulators may be alternating ridges (46) and valleys (48). The smaller turbulators may be concave surface features such as dimples (62) and grooves (54), and/or convex surface features such as bumps (58) and smaller ridges (52). An embodiment with convex turbulators (52, 58) in the valleys (48) and concave turbulators (54, 62) on the ridges (46) increases the cooling surface area, reduces boundary layer separation, avoids coolant shadowing and stagnation, and reduces component mass.

  3. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    AWEA). 2009b. AWEA Small Wind Turbine Global Market Study:will ultimately benefit wind. Small Wind ITC: EESA 2008

  4. Wave Decay in MHD Turbulence

    E-Print Network [OSTI]

    Andrey Beresnyak; Alex Lazarian

    2008-05-06

    We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.

  5. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    Public Service Wind Integration Cost Impact Study. Preparedequipment-related wind turbine costs, the overall importinstalled wind power project costs, wind turbine transaction

  6. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    Public Service Wind Integration Cost Impact Study. Preparedequipment-related wind turbine costs, the overall importinstalled wind power project costs, wind turbine transaction

  7. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    land- based wind energy technology. 2009 Wind TechnologiesRenewable Energy 2009 WIND TECHNOLOGIES MARKET REPORT AUGUSTfor a variety of energy technologies, including wind energy.

  8. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    land-based wind energy technology. 2011 Wind Technologiesfor a variety of energy technologies, including wind energy.Renewable Energy Laboratory’s National Wind Technology

  9. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    land-based wind energy technology. 2010 Wind Technologiesfor a variety of energy technologies, including wind energy.2010 Wind Technologies Market Report Federal Energy

  10. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01

    land-based wind energy technology. 2012 Wind Technologiesfor a variety of energy technologies, including wind energy.of Energy (DOE) Wind & Water Power Technology Office team

  11. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    wind power project costs, wind turbine transaction prices,increases in the cost of wind turbines over the last severaland components and wind turbine costs. Excluded from all

  12. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    A. 2010. Impact of Wind Energy Installations on DomesticJanuary 31, 2011. American Wind Energy Association (AWEA).D.C. : American Wind Energy Association. American Wind

  13. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    A. 2010. Impact of Wind Energy Installations on DomesticUniversity. American Wind Energy Association (AWEA). 2012a.D.C. : American Wind Energy Association. American Wind

  14. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    SciTech Connect (OSTI)

    Shupe, Matthew

    2013-05-22

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  15. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Shupe, Matthew

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  16. Wind Power Software

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

    Wind Analysis ms - 3.0MB Excel Excel Wind Analysis Presentation - 8.2MB PowerPoint Excel Wind Analysis With Power Curves Included - 3.7MB Excel WindR.exe - 44kB Weibull Excel Wind...

  17. Wind Integration

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAbout /Two0Photos andSeminarsDesign » DesignMay »helpWind

  18. Wind Power

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking WithTelecentricNCubicthe FOIA?ResourceMeasurement Buoy AdvancesWind

  19. Method for computing efficient electrical indicators for offshore wind turbine monitoring

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    by offshore deployment of wind farms. The offshore turbines have much lower accessibility(1) so maintenanceMethod for computing efficient electrical indicators for offshore wind turbine monitoring Georgia.cablea, pierre.granjon, christophe.berenguer} @gipsa-lab.grenoble-inp.fr Abstract Offshore wind turbines

  20. WIND ENERGY STUDIES OFFSHORE USING SATELLITE REMOTE SENSING MERETE BRUUN CHRISTIANSEN

    E-Print Network [OSTI]

    1 WIND ENERGY STUDIES OFFSHORE USING SATELLITE REMOTE SENSING MERETE BRUUN CHRISTIANSEN Wind Energy Dept., Risø National Laboratory Denmark Abstract The wind provides a rich energy source, which can be exploited further in order to reach the energy goals of accessibility, availability and acceptability set up

  1. INTRODUCTION Currently, wind turbines can incur unforeseen damage up to five times a year.

    E-Print Network [OSTI]

    Lynch, Jerome P.

    -13, 2007. Integral SHM-System for Offshore Wind Turbines Using Smart Wireless Sensors R ROLFES, S ZERBST, G1 1 INTRODUCTION Currently, wind turbines can incur unforeseen damage up to five times a year. Particularly during bad weather, wind turbines located offshore are difficult to access for visual inspection

  2. Responding to a Changing Energy Industry : 2007 Wind Energy Business Plan

    E-Print Network [OSTI]

    Jacobson, Ryan J.

    2007-12-14

    of the > MW > wind energy project in >. > acquired small wind energy developer > in 2004, giving them access to development rights to several projects in >, who has big plans for many small wind and other projects in the coming years. The current contract with > has been extended to 2008. Based...

  3. Magnetic helicity signature produced by cross-field 2D turbulence

    SciTech Connect (OSTI)

    Markovskii, S. A.; Vasquez, Bernard J.

    2013-06-13

    Hybrid numerical simulations of freely decaying 2D turbulence are presented. The background magnetic field is perpendicular to the simulation plane, which eliminates linear kinetic Alfven waves from the system. The normalized magnetic helicity of the initial large-scale fluctuations is zero, while the normalized cross-helicity is not. As the turbulence evolves, it develops nonzero magnetic helicity at smaller scales, in the proton kinetic range. In the quasi-steady state of evolution, the magnetic helicity spectrum has a peak consistent with the solar wind observations.

  4. Wind Power Today

    SciTech Connect (OSTI)

    Not Available

    2006-05-01

    Wind Power Today is an annual publication that provides an overview of the wind energy research conducted by the U.S. Department of Energy Wind and Hydropower Technologies Program.

  5. Stochastic model for aerodynamic force dynamics on wind turbine blades in unsteady wind inflow

    E-Print Network [OSTI]

    Luhur, Muhammad Ramzan; Kühn, Martin; Wächter, Matthias

    2015-01-01

    The paper presents a stochastic approach to estimate the aerodynamic forces with local dynamics on wind turbine blades in unsteady wind inflow. This is done by integrating a stochastic model of lift and drag dynamics for an airfoil into the aerodynamic simulation software AeroDyn. The model is added as an alternative to the static table lookup approach in blade element momentum (BEM) wake model used by AeroDyn. The stochastic forces are obtained for a rotor blade element using full field turbulence simulated wind data input and compared with the classical BEM and dynamic stall models for identical conditions. The comparison shows that the stochastic model generates additional extended dynamic response in terms of local force fluctuations. Further, the comparison of statistics between the classical BEM, dynamic stall and stochastic models' results in terms of their increment probability density functions gives consistent results.

  6. Scale Models & Wind Turbines

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

    Turbines * Readings about Cape Wind and other offshore and onshore siting debates for wind farms * Student Worksheet * A number of scale model items: Ken, Barbie or other dolls...

  7. Wind Power Outreach Campaign

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

    Wind Power Wind Power Main Page Outreach Programs Image Gallery FAQs Links Software Hydro Power INL Home Outreach Programs A team of educators and scientists from the Idaho...

  8. Wind/Hydro Study

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

    WindHydro Integration Feasibility Study Announcements (Updated July 8, 2010) The Final WindHydro Integration Feasibility Study Report, dated June 2, 2009, has been submitted to...

  9. Wind for Schools (Poster)

    SciTech Connect (OSTI)

    Baring-Gould, I.

    2010-05-01

    As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses, by installing small wind turbines at community "host" schools, by implementing teacher training with interactive curricula at each host school. This poster provides an overview of the first two years of the Wind for Schools project, primarily supporting activities in Colorado, Kansas, Nebraska, South Dakota, Montana, and Idaho.

  10. Wind energy bibliography

    SciTech Connect (OSTI)

    1995-05-01

    This bibliography is designed to help the reader search for information on wind energy. The bibliography is intended to help several audiences, including engineers and scientists who may be unfamiliar with a particular aspect of wind energy, university researchers who are interested in this field, manufacturers who want to learn more about specific wind topics, and librarians who provide information to their clients. Topics covered range from the history of wind energy use to advanced wind turbine design. References for wind energy economics, the wind energy resource, and environmental and institutional issues related to wind energy are also included.

  11. Small Wind Conference 2015

    Broader source: Energy.gov [DOE]

    The Small Wind Conference brings together small wind installers, site assessors, manufacturers, dealers and distributors, supply chain stakeholders, educators, public benefits program managers, and...

  12. Wind Turbine Tribology Seminar

    Broader source: Energy.gov [DOE]

    Wind turbine reliability issues are often linked to failures of contacting components, such as bearings, gears, and actuators. Therefore, special consideration to tribological design in wind...

  13. Characterizing Inflow Conditions Across the Rotor Disk of a Utility-Scale Wind Turbine (Poster)

    SciTech Connect (OSTI)

    Clifton, A.; Lundquist, J. K.; Kelley, N.; Scott, G.; Jager, D.; Schreck, S.

    2012-01-01

    Multi-megawatt utility-scale wind turbines operate in a turbulent, thermally-driven atmosphere where wind speed and air temperature vary with height. Turbines convert the wind's momentum into electrical power, and so changes in the atmosphere across the rotor disk influence the power produced by the turbine. To characterize the inflow into utility scale turbines at the National Wind Technology Center (NWTC) near Boulder, Colorado, NREL recently built two 135-meter inflow monitoring towers. This poster introduces the towers and the measurements that are made, showing some of the data obtained in the first few months of operation in 2011.

  14. For Cape Wind, Summer Breeze Makes Offshore Wind Feel Fine |...

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

    For Cape Wind, Summer Breeze Makes Offshore Wind Feel Fine For Cape Wind, Summer Breeze Makes Offshore Wind Feel Fine July 1, 2014 - 8:44am Addthis For Cape Wind, Summer Breeze...

  15. Turbulent AGN tori

    E-Print Network [OSTI]

    M. Schartmann; K. Meisenheimer; H. Klahr; M. Camenzind; S. Wolf; Th. Henning

    2008-08-05

    Recently, the MID-infrared Interferometric instrument (MIDI) at the VLTI has shown that dust tori in the two nearby Seyfert galaxies NGC 1068 and the Circinus galaxy are geometrically thick and can be well described by a thin, warm central disk, surrounded by a colder and fluffy torus component. By carrying out hydrodynamical simulations with the help of the TRAMP code (Klahr et al. 1999), we follow the evolution of a young nuclear star cluster in terms of discrete mass-loss and energy injection from stellar processes. This naturally leads to a filamentary large scale torus component, where cold gas is able to flow radially inwards. The filaments open out into a dense and very turbulent disk structure. In a post-processing step, we calculate observable quantities like spectral energy distributions or images with the help of the 3D radiative transfer code MC3D (Wolf 2003). Good agreement is found in comparisons with data due to the existence of almost dust-free lines of sight through the large scale component and the large column densities caused by the dense disk.

  16. the risk issue of wind measurement for wind turbine operation

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    Sciences, National Taiwan University #12;outline · Wind measurement in meteorology and wind farm design-related issues on wind turbine operation 3/31/2011 2 #12;WIND MEASUREMENT IN METEOROLOGY & WIND FARM DESIGN 3://www.atm.ncu.edu.tw/93/wind/ MM5 simulation (1996~2000 database) Wind speed (m/s) at 50mWind power (100W/m2) at 50m http://wind.itri.org.tw/wind

  17. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    of Energy’s (DOE) Wind & Water Power Program. For reviewingwere funded by the Wind & Water Power Program, Office ofWind Technologies Market Report Wind Energy Web Sites U.S. Department of Energy Wind and Water Power

  18. Helical mode interactions and spectral transfer processes in magnetohydrodynamic turbulence

    E-Print Network [OSTI]

    Moritz F. Linkmann; Arjun Berera; Mairi E. McKay; Julia Jäger

    2015-08-22

    Spectral transfer processes in magnetohydrodynamic (MHD) turbulence are investigated analytically by decomposition of the velocity and magnetic fields in Fourier space into helical modes. Steady solutions of the dynamical system which governs the evolution of the helical modes are determined, and a stability analysis of these solutions is carried out. The interpretation of the analysis is that unstable solutions lead to energy transfer between the interacting modes while stable solutions do not. From this, a dependence of possible interscale energy and helicity transfers on the helicities of the interacting modes is derived. As expected from the inverse cascade of magnetic helicity in 3D MHD turbulence, mode interactions with like helicities lead to transfer of energy and magnetic helicity to smaller wavenumbers. However, some interactions of modes with unlike helicities also contribute to an inverse energy transfer. As such, an inverse energy cascade for nonhelical magnetic fields is shown to be possible. Furthermore, it is found that high values of the cross-helicity may have an asymmetric effect on forward and reverse transfer of energy, where forward transfer is more quenched in regions of high cross-helicity than reverse transfer. This conforms with recent observations of solar wind turbulence. For specific helical interactions the relation to dynamo action is established.

  19. Helical mode interactions and spectral transfer processes in magnetohydrodynamic turbulence

    E-Print Network [OSTI]

    Moritz F. Linkmann; Arjun Berera; Mairi E. McKay; Julia Jäger

    2015-09-01

    Spectral transfer processes in magnetohydrodynamic (MHD) turbulence are investigated analytically by decomposition of the velocity and magnetic fields in Fourier space into helical modes. Steady solutions of the dynamical system which governs the evolution of the helical modes are determined, and a stability analysis of these solutions is carried out. The interpretation of the analysis is that unstable solutions lead to energy transfer between the interacting modes while stable solutions do not. From this, a dependence of possible interscale energy and helicity transfers on the helicities of the interacting modes is derived. As expected from the inverse cascade of magnetic helicity in 3D MHD turbulence, mode interactions with like helicities lead to transfer of energy and magnetic helicity to smaller wavenumbers. However, some interactions of modes with unlike helicities also contribute to an inverse energy transfer. As such, an inverse energy cascade for nonhelical magnetic fields is shown to be possible. Furthermore, it is found that high values of the cross-helicity may have an asymmetric effect on forward and reverse transfer of energy, where forward transfer is more quenched in regions of high cross-helicity than reverse transfer. This conforms with recent observations of solar wind turbulence. For specific helical interactions the relation to dynamo action is established.

  20. On the evolution of particle-puffs in turbulence

    E-Print Network [OSTI]

    Stefano Bianchi; Luca Biferale; Antonio Celani; Massimo Cencini

    2015-09-27

    We study the evolution of turbulent puffs by means of high-resolution numerical simulations. Puffs are bunches of passive particles released from an initially spherical distribution at regular time intervals of the order of the Kolmogorov time. The instantaneous shapes of particle puffs, in particular their asphericity and prolateness, are characterized by measuring the gyration tensor. Analysis has been performed by following, up to one large scale eddy-turn-over time, more than $10^4$ different puffs, each made of 2000 particle tracers, emitted from different places in a homogeneous and isotropic turbulent fluid with Taylor-scale Reynolds number $Re_\\lambda \\sim 300$. We also analyze the probability of hitting a given target placed downstream with respect to the local wind at the time of emission, presenting data for three different cases: (i) without any reconstruction of the shape, i.e. considering the bunch of point tracers, and approximating the particle-puff as a (ii) sphere or as an (iii) ellipsoid. The results show a strong dependence on the fluctuations of the instantaneous wind at the moment of the emission and appear to be robust with respect to the approximations (i)-(iii).

  1. Two-fluid turbulence including electron inertia

    SciTech Connect (OSTI)

    Andrés, Nahuel Gómez, Daniel; Gonzalez, Carlos; Martin, Luis; Dmitruk, Pablo

    2014-12-15

    We present a full two-fluid magnetohydrodynamic (MHD) description for a completely ionized hydrogen plasma, retaining the effects of the Hall current, electron pressure, and electron inertia. According to this description, each plasma species introduces a new spatial scale: the ion inertial length ?{sub i} and the electron inertial length ?{sub e}, which are not present in the traditional MHD description. In the present paper, we seek for possible changes in the energy power spectrum in fully developed turbulent regimes, using numerical simulations of the two-fluid equations in two-and-a-half dimensions. We have been able to reproduce different scaling laws in different spectral ranges, as it has been observed in the solar wind for the magnetic energy spectrum. At the smallest wavenumbers where plain MHD is valid, we obtain an inertial range following a Kolmogorov k{sup ?5?3} law. For intermediate wavenumbers such that ?{sub i}{sup ?1}?k??{sub e}{sup ?1}, the spectrum is modified to a k{sup ?7?3} power-law, as has also been obtained for Hall-MHD neglecting electron inertia terms. When electron inertia is retained, a new spectral region given by k>?{sub e}{sup ?1} arises. The power spectrum for magnetic energy in this region is given by a k{sup ?11?3} power law. Finally, when the terms of electron inertia are retained, we study the self-consistent electric field. Our results are discussed and compared with those obtained in the solar wind observations and previous simulations.

  2. Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent

    E-Print Network [OSTI]

    Martín, Pino

    Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent Boundary Layers the effect of turbulence fluctuations on surface heating rate by conducting direct numerical simulations (DNS subtle influence on the mean heating rate. We also find that the effect of turbulence

  3. Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers

    E-Print Network [OSTI]

    Martín, Pino

    Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers Lian reaction. The influence of chemical reactions on temperature fluctuation variance, Reynolds stresses that the recombination reaction enhances turbulence, while the dissociation reaction damps turbulence. Chemical reactions

  4. Choosing wind power plant locations and sizes based on electric reliability measures using multiple-year wind speed measurements

    SciTech Connect (OSTI)

    Milligan, M.R.; Artig, R.

    1999-07-08

    To project the US potential to meet future electricity demands with wind energy, estimates of available wind resource and costs to access that resource are critical. The US Department of Energy (DOE) Energy Information Administration (EIA) annually estimates the US market penetration of wind in its Annual Energy Outlook series. For these estimates, the EIA uses wind resource data developed by the Pacific Northwest National Laboratory for each region of the country. However, the EIA multiplies the cost of windpower by several factors, some as large as 3, to account for resource quality, market factors associated with accessing the resource, electric grid impacts, and rapid growth in the wind industry. This paper examines the rationale behind these additional costs and suggests alternatives.

  5. 3 - 4 Turbulent combustion Princeton.key

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

    speed (s T ) Turbulent RMS velocity in the fresh gas (u') Low turbulence zone s T a u' Bending zone Quenching l i m i t s L 0 Problem: these functions are configuration...

  6. Active skin for turbulent drag reduction 

    E-Print Network [OSTI]

    Mani, Raghavendran

    2002-01-01

    capitalizes on recent advances in active turbulent drag reduction and active material based actuation to develop an active or "smart" skin for turbulent drag reduction in realistic flight conditions. The skin operation principle is based on computational...

  7. WindWaveFloat Final Report

    SciTech Connect (OSTI)

    Alla Weinstein, Dominique Roddier, Kevin Banister

    2012-03-30

    Principle Power Inc. and National Renewable Energy Lab (NREL) have completed a contract to assess the technical and economic feasibility of integrating wave energy converters into the WindFloat, resulting in a new concept called the WindWaveFloat (WWF). The concentration of several devices on one platform could offer a potential for both economic and operational advantages. Wind and wave energy converters can share the electrical cable and power transfer equipment to transport the electricity to shore. Access to multiple generation devices could be simplified, resulting in cost saving at the operational level. Overall capital costs may also be reduced, provided that the design of the foundation can be adapted to multiple devices with minimum modifications. Finally, the WindWaveFloat confers the ability to increase energy production from individual floating support structures, potentially leading to a reduction in levelized energy costs, an increase in the overall capacity factor, and greater stability of the electrical power delivered to the grid. The research conducted under this grant investigated the integration of several wave energy device types into the WindFloat platform. Several of the resulting system designs demonstrated technical feasibility, but the size and design constraints of the wave energy converters (technical and economic) make the WindWaveFloat concept economically unfeasible at this time. Not enough additional generation could be produced to make the additional expense associated with wave energy conversion integration into the WindFloat worthwhile.

  8. An investigation of the relationships between mountain waves and clear air turbulence encountered by the XB-70 airplane in the stratosphere 

    E-Print Network [OSTI]

    Incrocci, Thomas Paul

    1970-01-01

    troposphere of the average profiles of L and Ri for those cases with wind components less than 10 m sec normal to the mountain tops 43 INTRODUCTION The problem of stratospheric turbulence was vividly brought to light when the supersonic XB-70 airplane...AN INVESTIGATION OF THE RELATIONSHIPS BETWEEN MOUNTAIN WAVES AND CLEAR AIR TURBULENCE ENCOUNTERED BY TIIE XB-70 AIRPLANE IN THE STRATOSPHERE A Thesis by THOMAS PAUL INCROCCI Submitted to the Graduate College of Texas A&M University...

  9. The role of the Kubo number in two-component turbulence

    SciTech Connect (OSTI)

    Qin, G. [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)] [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); Shalchi, A. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada)] [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada)

    2013-09-15

    We explore the random walk of magnetic field lines in two-component turbulence by using computer simulations. It is often assumed that the two-component model provides a good approximation for solar wind turbulence. We explore the dependence of the field line diffusion coefficient on the Kubo number which is a fundamental and characteristic quantity in the theory of turbulence. We show that there are two transport regimes. One is the well-known quasilinear regime in which the diffusion coefficient is proportional to the Kubo number squared, and the second one is a nonlinear regime in which the diffusion coefficient is directly proportional to the Kubo number. The so-called percolative transport regime which is often discussed in the literature cannot be found. The numerical results obtained in the present paper confirm analytical theories for random walking field lines developed in the past.

  10. Internet architecture Access networks

    E-Print Network [OSTI]

    architecture (1) router PC server wireless laptop smartphone Wired Communication links in router)/wireless access point Ethernet Wireless access point Wireless laptops Router links " connect end systems/routers/switches/access points " fiber, copper and radio " transmission rate

  11. Turbulent flow over a house in a simulated hurricane boundary layer

    E-Print Network [OSTI]

    Taylor, Zachary; Gurka, Roi; Kopp, Gregory

    2009-01-01

    Every year hurricanes and other extreme wind storms cause billions of dollars in damage worldwide. For residential construction, such failures are usually associated with roofs, which see the largest aerodynamic loading. However, determining aerodynamic loads on different portions of North American houses is complicated by the lack of clear load paths and non-linear load sharing in wood frame roofs. This problem of fluid-structure interaction requires both wind tunnel testing and full-scale structural testing. A series of wind tunnel tests have been performed on a house in a simulated atmospheric boundary layer (ABL), with the resulting wind-induced pressures applied to the full-scale structure. The ABL was simulated for flow over open country terrain where both velocity and turbulence intensity profiles, as well as spectra, were matched with available full scale measurements for this type of terrain. The first set of measurements was 600 simultaneous surface pressure measurements over the entire house. A key...

  12. Magnetic Field Rotations in the Solar Wind at Kinetic Scales

    E-Print Network [OSTI]

    Chen, C H K; Burgess, D; Horbury, T S

    2015-01-01

    The solar wind magnetic field contains rotations at a broad range of scales, which have been extensively studied in the MHD range. Here we present an extension of this analysis to the range between ion and electron kinetic scales. The distribution of rotation angles was found to be approximately log-normal, shifting to smaller angles at smaller scales almost self-similarly, but with small, statistically significant changes of shape. The fraction of energy in fluctuations with angles larger than $\\alpha$ was found to drop approximately exponentially with $\\alpha$, with e-folding angle $9.8^\\circ$ at ion scales and $0.66^\\circ$ at electron scales, showing that large angles ($\\alpha > 30^\\circ$) do not contain a significant amount of energy at kinetic scales. Implications for kinetic turbulence theory and the dissipation of solar wind turbulence are discussed.

  13. Numerical Study of a Turbulent Hydraulic Jump

    E-Print Network [OSTI]

    Zhao, Qun

    Numerical Study of a Turbulent Hydraulic Jump Qun Zhao, Shubhra Misra, Ib. A. Svendsen and James T of a Turbulent Hydraulic Jump ­ p.1/14 #12;Objective Our ultimate goal is to study the breaking waves. Numerical Study of a Turbulent Hydraulic Jump ­ p.2/14 #12;A moving bore Qiantang Bore China (Courtesy of Dr J

  14. Turbulence Induced Transport in Tokamaks

    SciTech Connect (OSTI)

    Caldas, I. L.; Marcus, F. A.; Heller, M. V. A. P.; Guimaraes-Filho, Z. O. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970, Sao Paulo, SP (Brazil); Batista, A. M. [Departamento de Matematica e Estatistica, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR (Brazil); Viana, R. L.; Lopes, S. R. [Departamento de Fisica, Universidade Federal do Parana, 81531-990, Curitiba, PR (Brazil); Morrison, P. J.; Horton, W. [Department of Physics, University of Texas at Austin, Austin, Texas, 78712 (United States); Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas, 78712 (United States)

    2006-12-04

    This report is concerned with plasma edge turbulence and its relation to anomalous particle transport in tokamaks. First, experimental evidence of turbulence driven particle transport and measurements of the gradients of the equilibrium profiles in the Brazilian tokamaks TBR and TCABR are presented. Next, diffusion in a two drift-wave system is discussed. In this nonintegrable system, particle transport is associated with the onset of chaotic orbits. Finally, numerical evidence suggesting that a nonlinear three-mode interaction could contribute to the intermittent plasma fluctuations observed in tokamaks is presented.

  15. Estimation of Wind Speed in Connection to a Wind Turbine

    E-Print Network [OSTI]

    Estimation of Wind Speed in Connection to a Wind Turbine X. Ma #3; , N. K. Poulsen #3; , H. Bindner y December 20, 1995 Abstract The wind speed varies over the rotor plane of wind turbine making the wind speed on the rotor plane will be estimated by using a wind turbine as a wind measuring device

  16. Wind energy offers considerable promise; the wind itself is free,

    E-Print Network [OSTI]

    Langendoen, Koen

    Wind energy offers considerable promise; the wind itself is free, wind power is clean. One of these sources, wind energy, offers considerable promise; the wind itself is free, wind power is clean, and it is virtually inexhaustible. In recent years, research on wind energy has accelerated

  17. Wind Resource Maps (Postcard)

    SciTech Connect (OSTI)

    Not Available

    2011-07-01

    The U.S. Department of Energy's Wind Powering America initiative provides high-resolution wind maps and estimates of the wind resource potential that would be possible from development of the available windy land areas after excluding areas unlikely to be developed. This postcard is a marketing piece that stakeholders can provide to interested parties; it will guide them to Wind Powering America's online wind energy resource maps.

  18. Gravitational Collapse in Turbulent Molecular Clouds. II. Magnetohydrodynamical Turbulence

    E-Print Network [OSTI]

    F. Heitsch; M. -M. Mac Low; R. S. Klessen

    2000-09-14

    Hydrodynamic supersonic turbulence can only prevent local gravitational collapse if the turbulence is driven on scales smaller than the local Jeans lengths in the densest regions, a very severe requirement (Paper I). Magnetic fields have been suggested to support molecular clouds either magnetostatically or via magnetohydrodynamic (MHD) waves. Whereas the first mechanism would form sheet-like clouds, the second mechanism not only could exert a pressure onto the gas counteracting the gravitational forces, but could lead to a transfer of turbulent kinetic energy down to smaller spatial scales via MHD wave interactions. This turbulent magnetic cascade might provide sufficient energy at small scales to halt local collapse. We test this hypothesis with MHD simulations at resolutions up to 256^3 zones, done with ZEUS-3D. We first derive a resolution criterion for self-gravitating, magnetized gas: in order to prevent collapse of magnetostatically supported regions due to numerical diffusion, the minimum Jeans length must be resolved by four zones. Resolution of MHD waves increases this requirement to roughly six zones. We then find that magnetic fields cannot prevent local collapse unless they provide magnetostatic support. Weaker magnetic fields do somewhat delay collapse and cause it to occur more uniformly across the supported region in comparison to the hydrodynamical case. However, they still cannot prevent local collapse for much longer than a global free-fall time.

  19. MHD Waves and Coronal Heating: Unifying Empirical and MHD Turbulence Models

    E-Print Network [OSTI]

    Sokolov, Igor V; Oran, Rona; Downs, Cooper; Roussev, Ilia I; Jin, Meng; Manchester, Ward B; Evans, Rebekah M; Gombosi, Tamas I

    2012-01-01

    We present a new global model of the solar corona, including the low corona, the transition region and the top of chromosphere. The realistic 3D magnetic field is simulated using the data from the photospheric magnetic field measurements. The distinctive feature of the new model is incorporating the MHD Alfven wave turbulence. We assume this turbulence and its non-linear dissipation to be the only momentum and energy source for heating the coronal plasma and driving the solar wind. The difference between the turbulence dissipation efficiency in coronal holes and that in closed field regions is because the non-linear cascade rate degrades in strongly anisotropic turbulence in coronal holes (no inward propagating wave), thus resulting in colder coronal holes with the bi-modal solar wind originating from them. The detailed presentation of the theoretical model is illustrated with the synthetic images for multi-wavelength EUV emission compared with the observations from SDO AIA and Stereo EUVI instruments for the...

  20. Sinomatech Wind Power Blade aka Sinoma Science Technology Wind...

    Open Energy Info (EERE)

    Sinomatech Wind Power Blade aka Sinoma Science Technology Wind Turbine Blade Co Ltd Jump to: navigation, search Name: Sinomatech Wind Power Blade (aka Sinoma Science & Technology...

  1. Wind energy offers considerable promise

    E-Print Network [OSTI]

    Langendoen, Koen

    Wind energy offers considerable promise: the wind itself is free, wind power is clean: the wind itself is free, wind power is clean, and it is inexhaustible. In recent years, research on wind · Wind farm aerodynamics Rotor Design · Aerodynamics · Structure and design · Composite design, material

  2. Final report: Task 4a.2 20% wind scenario assessment of electric grid operational features

    SciTech Connect (OSTI)

    Toole, Gasper L.

    2009-01-01

    Wind integration modeling in electricity generation capacity expansion models is important in that these models are often used to inform political or managerial decisions. Poor representation of wind technology leads to under-estimation of wind's contribution to future energy scenarios which may hamper growth of the industry. The NREL's Wind Energy Deployment System (WinDS) model provides the most detailed representation of geographically disperse renewable resources and the optimization of transmission expansion to access these resources. Because WinDS was selected as the primary modeling tool for the 20% Wind Energy by 2030 study, it is the ideal tool for supplemental studies of the transmission expansion results. However, as the wind industry grows and knowledge related to the wind resource and integration of wind energy into the electric system develops, the WinDS model must be continually improved through additional data and innovative algorithms to capture the primary effects of variable wind generation. The detailed representation of wind technology in the WinDS model can be used to provide improvements to the simplified representation of wind technology in other capacity expansion models. This task did not employ the WinDS model, but builds from it and its results. Task 4a.2 provides an assessment of the electric grid operational features of the 20% Wind scenario and was conducted using power flow models accepted by the utility industry. Tasks 2 provides information regarding the physical flow of electricity on the electric grid which is a critical aspect of infrastructure expansion scenarios. Expanding transmission infrastructure to access remote wind resource in a physically realizable way is essential to achieving 20% wind energy by 2030.

  3. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle June 1, 2005 ­ August 31, 2005 Prepared for United States Department...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  4. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle December 1, 2004 ­ February 28, 2005 Prepared for United States.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  5. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle December 1, 2004 ­ December 1, 2005 Prepared for United States ......................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  6. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2003 ­ August 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  7. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island December 1, 2003 ­ February 29, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution

  8. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle March 1, 2005 ­ May 31, 2005 Prepared for United States Department.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  9. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2003 ­ May 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  10. WIND DATA REPORT FALMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT FALMOUTH, MA June1, 2004 to August 31, 2004. Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 8 Wind Speed Distributions

  11. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island September 1, 2003 ­ November 30, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  12. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2004 ­ May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  13. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2004 ­ August 31, 2004 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  14. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01

    with the section on offshore wind; Donna Heimiller and Billyof 2012, global cumulative offshore wind capacity stood ats (DOE’s) investments in offshore wind energy research and

  15. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    11 “advanced-stage” offshore wind project proposals totalingcontinued in 2008 (see Offshore Wind Development Activities,Market Report Offshore Wind Development Activities In

  16. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    for deepwater offshore wind and tidal energy demonstrationand Minnesota (12%). Offshore Wind Power Project and Policythe emergence of an offshore wind power market still faces

  17. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    and Minnesota (12%). Offshore Wind Power Project and Policythe emergence of an offshore wind power market still facesexists in developing offshore wind energy in several parts

  18. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    of Energy?s (DOE) Wind & Water Power Program. For reviewingfor offshore wind power development in federal waters fromof Water and Power (LADWP). 2011. Completion of Wind Power

  19. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    Table 8 Figure 30. Wind Integration Costs at Various LevelsOperations and Maintenance Costs Wind project operations andPublic Service Wind Integration Cost Impact Study. Prepared

  20. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    charging wind power projects for balancing services. 81 BPA,in balancing reserves with increased wind power penetrationin balancing reserves with increased wind power penetration

  1. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    charging wind power projects for balancing services. 88 BPA,in balancing reserves with increased wind power penetrationin balancing reserves with increased wind power penetration

  2. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01

    Xcel Energy. 2011. Wind Induced Coal Plant Cyclingand the Implications of Wind Curtailment for Public Serviceof Colorado 2 GW and 3 GW Wind Integration Cost Study.

  3. Wind Farms in North America

    E-Print Network [OSTI]

    Hoen, Ben

    2014-01-01

    Opinion About Large Offshore Wind Power: Underlying Factors.Delaware Opinion on Offshore Wind Power - Interim Report.Newark, DE. 16 pages. Global Wind Energy Council (GWEC) (

  4. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    be provided by wind power generators to provide frequencyof wind power capacity in that state) because generatorsgenerators to provide the needed flexibility to integrate wind power.

  5. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    2010. Status of Centralized Wind Power Forecasting in NorthInterconnection Policies and Wind Power: A Discussion ofLADWP). 2011. Completion of Wind Power Project Brings More

  6. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    and K. Porter. 2011. Wind Power and Electricity Markets.The Effects of Integrating Wind Power on Transmission System41 6. Wind Power Price

  7. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    exists in developing offshore wind energy in several partsexclusively on offshore wind energy will be published laterexclusively on offshore wind energy will be published later

  8. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    assistance with the offshore wind energy discussion; Donnaactivity in the offshore wind energy sector. Data fromexpanded discussion of offshore wind energy development, and

  9. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    exists in developing offshore wind energy in several partsstrides relating to offshore wind energy have been madeactivity in the offshore wind energy sector. Data from

  10. WIND DATA REPORT Nantucket, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Nantucket, MA March 1st 2006 to May 31th 2006 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribut

  11. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    2010. International Wind Energy Development: World MarketUniversity. American Wind Energy Association (AWEA). 2010a.Washington, DC: American Wind Energy Association. American

  12. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    2008. Washington, DC: American Wind Energy Association.American Wind Energy Association ( AWEA). 2009b. AWEA SmallWashington, DC: American Wind Energy Association. Bolinger,

  13. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    2008. Washington, DC: American Wind Energy Association.American Wind Energy Association ( AWEA).2009b. AWEA Small Wind Turbine Global Market Study: Year

  14. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    Prepared for the Utility Wind Integration Group. Arlington,Consult. 2010. International Wind Energy Development: WorldUBS Global I/O: Global Wind Sector. UBS Investment Research.

  15. AWEA Wind Energy Fall Symposium

    Broader source: Energy.gov [DOE]

    The AWEA Wind Energy Fall Symposium gathers wind energy professionals for informal yet productive interactions with industry peers. Jose Zayas, Director, Wind & Water Power Technologies Office,...

  16. Validity of the Taylor hypothesis for linear kinetic waves in the weakly collisional solar wind

    SciTech Connect (OSTI)

    Howes, G. G.; Klein, K. G.; TenBarge, J. M.

    2014-07-10

    The interpretation of single-point spacecraft measurements of solar wind turbulence is complicated by the fact that the measurements are made in a frame of reference in relative motion with respect to the turbulent plasma. The Taylor hypothesis—that temporal fluctuations measured by a stationary probe in a rapidly flowing fluid are dominated by the advection of spatial structures in the fluid rest frame—is often assumed to simplify the analysis. But measurements of turbulence in upcoming missions, such as Solar Probe Plus, threaten to violate the Taylor hypothesis, either due to slow flow of the plasma with respect to the spacecraft or to the dispersive nature of the plasma fluctuations at small scales. Assuming that the frequency of the turbulent fluctuations is characterized by the frequency of the linear waves supported by the plasma, we evaluate the validity of the Taylor hypothesis for the linear kinetic wave modes in the weakly collisional solar wind. The analysis predicts that a dissipation range of solar wind turbulence supported by whistler waves is likely to violate the Taylor hypothesis, while one supported by kinetic Alfvén waves is not.

  17. Wind Power Career Chat

    SciTech Connect (OSTI)

    L. Flowers

    2011-01-01

    This document will teach students about careers in the wind energy industry. Wind energy, both land-based and offshore, is expected to provide thousands of new jobs in the next several decades. Wind energy companies are growing rapidly to meet America's demand for clean, renewable, and domestic energy. These companies need skilled professionals. Wind power careers will require educated people from a variety of areas. Trained and qualified workers manufacture, construct, operate, and manage wind energy facilities. The nation will also need skilled researchers, scientists, and engineers to plan and develop the next generation of wind energy technologies.

  18. BP8.00119 Solar Coronal Heating and Magnetic Energy Build-Up in a Tectonics Model1 , M. GILSON, C.S. NG, A. BHATTACHARJEE, Center for Integrated Computation and Analysis of Reconnection and Turbulence and Center for Magnetic Self-

    E-Print Network [OSTI]

    Ng, Chung-Sang

    .S. NG, A. BHATTACHARJEE, Center for Integrated Computation and Analysis of Reconnection and Turbulence Spectral Scaling on the Heating of the Solar Wind1 , D. MUNSI, C.S. NG, A. BHATTACHARJEE, P.A. ISENBERG Turbulence1 , C.S. NG, A. BHATTACHARJEE, Center for Integrated Computation and Analysis of Reconnection

  19. Synergistic Effects of Turbine Wakes and Atmospheric Stability on Power Production at an Onshore Wind Farm

    SciTech Connect (OSTI)

    Wharton, S; Lundquist, J K; Marjanovic, N

    2012-01-25

    This report examines the complex interactions between atmospheric stability and turbine-induced wakes on downwind turbine wind speed and power production at a West Coast North American multi-MW wind farm. Wakes are generated when the upwind flow field is distorted by the mechanical movement of the wind turbine blades. This has two consequences for downwind turbines: (1) the downwind turbine encounters wind flows with reduced velocity and (2) the downwind turbine encounters increased turbulence across multiple length scales via mechanical turbulence production by the upwind turbine. This increase in turbulence on top of ambient levels may increase aerodynamic fatigue loads on the blades and reduce the lifetime of turbine component parts. Furthermore, ambient atmospheric conditions, including atmospheric stability, i.e., thermal stratification in the lower boundary layer, play an important role in wake dissipation. Higher levels of ambient turbulence (i.e., a convective or unstable boundary layer) lead to higher turbulent mixing in the wake and a faster recovery in the velocity flow field downwind of a turbine. Lower levels of ambient turbulence, as in a stable boundary layer, will lead to more persistent wakes. The wake of a wind turbine can be divided into two regions: the near wake and far wake, as illustrated in Figure 1. The near wake is formed when the turbine structure alters the shape of the flow field and usually persists one rotor diameter (D) downstream. The difference between the air inside and outside of the near wake results in a shear layer. This shear layer thickens as it moves downstream and forms turbulent eddies of multiple length scales. As the wake travels downstream, it expands depending on the level of ambient turbulence and meanders (i.e., travels in non-uniform path). Schepers estimates that the wake is fully expanded at a distance of 2.25 D and the far wake region begins at 2-5 D downstream. The actual distance traveled before the wake recovers to its inflow velocity is dependent on the amount ambient turbulence, the amount of wind shear, and topographical and structural effects. The maximum velocity deficit is estimated to occur at 1-2 D but can be longer under low levels of ambient turbulence. Our understanding of turbine wakes comes from wind tunnel experiments, field experiments, numerical simulations, and from studies utilizing both experimental and modeling methods. It is well documented that downwind turbines in multi-Megawatt wind farms often produce less power than upwind turbine rows. These wake-induced power losses have been estimated from 5% to up to 40% depending on the turbine operating settings (e.g., thrust coefficient), number of turbine rows, turbine size (e.g., rotor diameter and hub-height), wind farm terrain, and atmospheric flow conditions (e.g., ambient wind speed, turbulence, and atmospheric stability). Early work by Elliott and Cadogan suggested that power data for different turbulent conditions be segregated to distinguish the effects of turbulence on wind farm power production. This may be especially important for downwind turbines within wind farms, as chaotic and turbulent wake flows increase stress on downstream turbines. Impacts of stability on turbine wakes and power production have been examined for a flat terrain, moderate size (43 turbines) wind farm in Minnesota and for an offshore, 80 turbine wind farm off the coast of Denmark. Conzemius found it difficult to distinguish wakes (i.e., downwind velocity deficits) when the atmosphere was convective as large amounts of scatter were present in the turbine nacelle wind speed data. This suggested that high levels of turbulence broke-up the wake via large buoyancy effects, which are generally on the order of 1 km in size. On the other hand, they found pronounced wake effects when the atmosphere was very stable and turbulence was either suppressed or the length scale was reduced as turbulence in this case was mechanically produced (i.e., friction forces). This led to larger reductions at downwind turbines and maximum ve

  20. EERE 2014 Wind Technologies Market Report Finds Wind Power at...

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

    2014 Wind Technologies Market Report Finds Wind Power at Record Low Prices EERE 2014 Wind Technologies Market Report Finds Wind Power at Record Low Prices August 10, 2015 - 11:00am...

  1. 20% Wind Energy by 2030: Increasing Wind Energy's Contribution...

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

    20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply 20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply...

  2. 2008 Wind Energy Projects, Wind Powering America (Poster)

    SciTech Connect (OSTI)

    Not Available

    2009-01-01

    The Wind Powering America program produces a poster at the end of every calendar year that depicts new U.S. wind energy projects. The 2008 poster includes the following projects: Stetson Wind Farm in Maine; Dutch Hill Wind Farm in New York; Grand Ridge Wind Energy Center in Illinois; Hooper Bay, Alaska; Forestburg, South Dakota; Elbow Creek Wind Project in Texas; Glacier Wind Farm in Montana; Wray, Colorado; Smoky Hills Wind Farm in Kansas; Forbes Park Wind Project in Massachusetts; Spanish Fork, Utah; Goodland Wind Farm in Indiana; and the Tatanka Wind Energy Project on the border of North Dakota and South Dakota.

  3. Momentum Flux Budget across the AirSea Interface under Uniform and Tropical Cyclone Winds

    E-Print Network [OSTI]

    Rhode Island, University of

    into ocean currents is equal to the flux from air (wind stress). However, when the surface wave field grows into currents under TCs. 1. Introduction The passage of a tropical cyclone (TC) over a warm ocean represents one is mainly due to the vertical turbulent mixing induced by the strong momentum flux into ocean currents

  4. Euler-Bernoulli Implementation of Spherical Anemometers for High Wind Speed Calculations via Strain Gauges 

    E-Print Network [OSTI]

    Castillo, Davis

    2011-08-08

    New measuring methods continue to be developed in the field of wind anemometry for various environments subject to low-speed and high-speed flows, turbulent-present flows, and ideal and non-ideal flows. As a result, anemometry has taken different...

  5. Near-surface meteorological conditions associated with active resuspension of dust by wind erosion

    SciTech Connect (OSTI)

    Hodgin, C.R.

    1982-01-01

    The meteorological conditions associated with extreme winds in the lee of the Colorado Rocky Mountains were studied from the viewpoint of dust resuspension and dispersion. Wind, dispersion, temperature, and dew point conditions occurring near the surface were discussed in detail for a selected event. Near-surface wind speeds were compared to observations made at a standard sampling height. These field data were developed to aid in validation and interpretation of wind tunnel observations and application of dispersion models to wind erosion resuspension. Three conclusions can immediately be drawn from this investigation. First, wind storms in nature are quite gusty, with gusts exceeding the mean speed by 50 percent or more. However, wind direction variations are small by comparison. Thus, wind tunnel studies should be able to simulate the large along-flow turbulence, while keeping cross-flow turbulence to a moderate level. This also has an application to the puff modeling of high winds. Puff models normally assume that the along-flow dispersion coefficient is equal to the cross-flow value. This study suggests that the along-flow coefficient should be much larger than its cross-flow counterpart. Another conclusion involves the usual assumption of Pasquill-Gifford stability class D. In the event studied here, the atmosphere was well mixed with near-neutral thermal stability, yet the horizontal dispersion stability class varied from G to A. Thus, an assumption of Class D horizontal dispersion during high winds would not have been valid during this case. A final conclusion involves the widely applied assumption of a logarithmic wind speed profile during high wind events. This study has indicated that such an assumption is appropriate.

  6. Distributed Wind 2015

    Broader source: Energy.gov [DOE]

    Distributed Wind 2015 is committed to the advancement of both distributed and community wind energy. This two day event includes a Business Conference with sessions focused on advancing the...

  7. Wind Power FAQ

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

    Power Frequently Asked Questions QUESTION: Why was the time stamp on my first wind explorer data chip incorrect? ANSWER: You need to program the proper date and time in the wind...

  8. Airplane and the wind

    E-Print Network [OSTI]

    Airplane and the wind. An airplane starts from the point A and flies to B. The speed of the airplane with respect to the air is v (constant). There is also a wind of

  9. NREL: Wind Research - Events

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

    Events Below are upcoming events related to wind energy technology. December 2015 Wind and Water Power Small Business Voucher Open House December 2, 2015, 9:00 - 1:00 MST Boulder,...

  10. WINDExchange: Learn About Wind

    Wind Powering America (EERE)

    wind turbines in a row at sunset. The sky is varying hues of orange and the sun is halfway past the horizon. Wind power comes in many sizes. Here, several...

  11. Residential Wind Power

    E-Print Network [OSTI]

    Willis, Gary

    2011-12-16

    This research study will explore the use of residential wind power and associated engineering and environmental issues. There is various wind power generating devices available to the consumer. The study will discuss the dependencies of human...

  12. After the Wind Storm 

    E-Print Network [OSTI]

    Unknown

    2011-09-05

    Accidents and hazards continue to plague the construction industry. One often overlooked hazard to workers is the potential for flying debris and materials during high winds. This research was designed to evaluate the wind velocity required...

  13. Turbulent equipartitions in two dimensional drift convection

    SciTech Connect (OSTI)

    Isichenko, M.B.; Yankov, V.V.

    1995-07-25

    Unlike the thermodynamic equipartition of energy in conservative systems, turbulent equipartitions (TEP) describe strongly non-equilibrium systems such as turbulent plasmas. In turbulent systems, energy is no longer a good invariant, but one can utilize the conservation of other quantities, such as adiabatic invariants, frozen-in magnetic flux, entropy, or combination thereof, in order to derive new, turbulent quasi-equilibria. These TEP equilibria assume various forms, but in general they sustain spatially inhomogeneous distributions of the usual thermodynamic quantities such as density or temperature. This mechanism explains the effects of particle and energy pinch in tokamaks. The analysis of the relaxed states caused by turbulent mixing is based on the existence of Lagrangian invariants (quantities constant along fluid-particle or other orbits). A turbulent equipartition corresponds to the spatially uniform distribution of relevant Lagrangian invariants. The existence of such turbulent equilibria is demonstrated in the simple model of two dimensional electrostatically turbulent plasma in an inhomogeneous magnetic field. The turbulence is prescribed, and the turbulent transport is assumed to be much stronger than the classical collisional transport. The simplicity of the model makes it possible to derive the equations describing the relaxation to the TEP state in several limits.

  14. Active control for turbulent premixed flame simulations

    SciTech Connect (OSTI)

    Bell, John B.; Day, Marcus S.; Grcar, Joseph F.; Lijewski, Michael J.

    2004-03-26

    Many turbulent premixed flames of practical interest are statistically stationary. They occur in combustors that have anchoring mechanisms to prevent blow-off and flashback. The stabilization devices often introduce a level of geometric complexity that is prohibitive for detailed computational studies of turbulent flame dynamics. As a result, typical detailed simulations are performed in simplified model configurations such as decaying isotropic turbulence or inflowing turbulence. In these configurations, the turbulence seen by the flame either decays or, in the latter case, increases as the flame accelerates toward the turbulent inflow. This limits the duration of the eddy evolutions experienced by the flame at a given level of turbulent intensity, so that statistically valid observations cannot be made. In this paper, we apply a feedback control to computationally stabilize an otherwise unstable turbulent premixed flame in two dimensions. For the simulations, we specify turbulent in flow conditions and dynamically adjust the integrated fueling rate to control the mean location of the flame in the domain. We outline the numerical procedure, and illustrate the behavior of the control algorithm. We use the simulations to study the propagation and the local chemical variability of turbulent flame chemistry.

  15. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    AWEA). 2009b. AWEA Small Wind Turbine Global Market Study:will ultimately benefit wind. Small Wind ITC: EESA 2008to be relatively small, whereas the impacts of wind on load-

  16. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    AWEA). 2010. AWEA Small Wind Turbine Global Market Survey,levels. Small Wind Turbines Small wind turbines can providebelow summarizes sales of small wind turbines, 100 kW and

  17. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    wind project costs, wind turbine transaction prices, projectincreases in the cost of wind turbines over the last severalO&M costs given the dramatic changes in wind turbine

  18. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    AWEA’s Wind Energy Weekly, DOE/EPRI’s Turbine Verification10% Wind Energy Penetration New large-scale 8 wind turbines100 wind turbine installed at the National Renewable Energy

  19. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    Sites U.S. Department of Energy Wind Program wind.energy.govA. 2010. Impact of Wind Energy Installations on DomesticUniversity. American Wind Energy Association (AWEA). 2012a.

  20. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    AWEA). 2012b. 2011 U.S. Small Wind Turbine Market Report.a brief discussion on Small Wind This 100 kW thresholdAnnual Capacity (GW) Small Wind Turbines Small wind turbines

  1. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01

    a brief discussion on Small Wind Turbines is provided onO&M costs. 2012 Wind Technologies Market Report Small WindTurbines Small wind turbines can provide power directly to

  2. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    AWEA). 2010. AWEA Small Wind Turbine Global Market Survey,a brief discussion on Small Wind Turbines is provided onat 2008 and 2009 levels. Small Wind Turbines Small wind

  3. A comparison of measured wind park load histories with the WISPER and WISPERX load spectra

    SciTech Connect (OSTI)

    Kelley, N.D.

    1995-01-01

    The blade-loading histories from two adjacent Micon 65/13 wind turbines are compared with the variable-amplitude test-loading histories known as the WISPER and WISPERX spectra. These standardized loading sequences were developed from blade flapwise load histories taken from nine different horizontal-axis wind turbines operating under a wide range of conditions in Europe. The subject turbines covered a broad spectrum of rotor diameters, materials, and operating environments. The final loading sequences were developed as a joint effort of thirteen different European organizations. The goal was to develop a meaningful loading standard for horizontal-axis wind turbine blades that represents common interaction effects seen in service. In 1990, NREL made extensive load measurements on two adjacent Micon 65/13 wind turbines in simultaneous operation in the very turbulent environment of a large wind park. Further, before and during the collection of the loads data, comprehensive measurements of the statistics of the turbulent environment were obtained at both the turbines under test and at two other locations within the park. The trend to larger but lighter wind turbine structures has made an understanding of the expected lifetime loading history of paramount importance. Experience in the US has shown that the turbulence-induced loads associated with multi-row wind parks in general are much more severe than for turbines operating individually or within widely spaced environments. Multi-row wind parks are much more common in the US than in Europe. In this paper we report on our results in applying the methodology utilized to develop the WISPER and WISPERX standardized loading sequences using the available data from the Micon turbines. While the intended purpose of the WISPER sequences were not to represent a specific operating environment, we believe the exercise is useful, especially when a turbine design is likely to be installed in a multi-row wind park.

  4. Wind Webinar Text Version

    Broader source: Energy.gov [DOE]

    Download the text version of the audio from the DOE Office of Indian Energy webinar on wind renewable energy.

  5. Wind Tunnel Building - 7 

    E-Print Network [OSTI]

    Unknown

    2005-06-30

    or gravitational energy to some extent. Moreover, wave energy provides “15-20 times more available energy per square meter than either wind or solar” [1]. Of these the most commercially viable resources studied so far are ocean currents and waves. Some... limited commercial development and is therefore of more interest. Ocean waves arise from the transfer of energy from the sun to wind then water. Solar energy creates wind, which then blows over the ocean, converting wind energy to wave energy. Once...

  6. Wind powering America: Vermont

    SciTech Connect (OSTI)

    NREL

    2000-04-11

    Wind resources in the state of Vermont show great potential for wind energy development according to the wind resource assessment conducted by the state, its utilities, and NREL. This fact sheet provides a brief description of the resource assessment and a link to the resulting wind resource map produced by NREL. The fact sheet also provides a description of the state's net metering program, its financial incentives, and green power programs as well as a list of contacts for more information.

  7. WP2 IEA Wind Task 26:The Past and Future Cost of Wind Energy

    E-Print Network [OSTI]

    Lantz, Eric

    2014-01-01

    Prospects for Offshore Wind Farms. ” Wind Engineering, 28:Techniques for Offshore Wind Farms. ” Journal of Solar

  8. Wind Farms in North America

    E-Print Network [OSTI]

    Hoen, Ben

    2014-01-01

    Opinion About Large Offshore Wind Power: Underlying Factors.Delaware Opinion on Offshore Wind Power - Interim Report.

  9. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    by Canada (76%) and Mexico (17%). Wind turbine component30%), Mexico (21%), and China (21%)). Total wind turbine

  10. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    of larger balancing areas, the use of regional wind powerbalancing areas. The successful use of regional wind power

  11. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    directly charging wind power projects for balancing servicesin smaller balancing areas. The successful use of wind power

  12. Wind Farms in North America

    E-Print Network [OSTI]

    Hoen, Ben

    2014-01-01

    Public Opinion About Large Offshore Wind Power: UnderlyingA. (2007) Delaware Opinion on Offshore Wind Power - Interim

  13. Wind Farms in North America

    E-Print Network [OSTI]

    Hoen, Ben

    2014-01-01

    Renewable Energy (Wind and Water Technologies Program) ofWind Farms in North America 1 Ben Hoen Environmental Energy Technologies

  14. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01

    regulation and frequency response services charge to wind energyRegulation and Frequency Response Service rate for wind energy

  15. Wind for Schools Curriculum Brief

    SciTech Connect (OSTI)

    None

    2010-08-01

    This fact sheet provides an overview of wind energy curricula as it relates to the Wind for Schools project.

  16. Open Access Task Force Open Access to

    E-Print Network [OSTI]

    Jiang, Huiqiang

    Libraries Initiative launched by National Science Foundation; Social Sciences Research Network (SSRN Library System rgmiller@pitt.edu #12;Open Access Task Force Open Access is... · A family of copyright · The only constraint on reproduction and distribution, and the only role for copyright in this domain

  17. Wind farm electrical system

    DOE Patents [OSTI]

    Erdman, William L.; Lettenmaier, Terry M.

    2006-07-04

    An approach to wind farm design using variable speed wind turbines with low pulse number electrical output. The output of multiple wind turbines are aggregated to create a high pulse number electrical output at a point of common coupling with a utility grid network. Power quality at each individual wind turbine falls short of utility standards, but the aggregated output at the point of common coupling is within acceptable tolerances for utility power quality. The approach for aggregating low pulse number electrical output from multiple wind turbines relies upon a pad mounted transformer at each wind turbine that performs phase multiplication on the output of each wind turbine. Phase multiplication converts a modified square wave from the wind turbine into a 6 pulse output. Phase shifting of the 6 pulse output from each wind turbine allows the aggregated output of multiple wind turbines to be a 24 pulse approximation of a sine wave. Additional filtering and VAR control is embedded within the wind farm to take advantage of the wind farm's electrical impedence characteristics to further enhance power quality at the point of common coupling.

  18. CONGRESSIONAL BRIEFING Offshore Wind

    E-Print Network [OSTI]

    Firestone, Jeremy

    CONGRESSIONAL BRIEFING Offshore Wind Lessons Learned from Europe: Reducing Costs and Creating Jobs Thursday, June 12, 2014 Capitol Visitors Center, Room SVC 215 Enough offshore wind capacity to power six the past decade. What has Europe learned that is applicable to a U.S. effort to deploy offshore wind off

  19. Wind Economic Development (Postcard)

    SciTech Connect (OSTI)

    Not Available

    2011-08-01

    The U.S. Department of Energy's Wind Powering America initiative provides information on the economic development benefits of wind energy. This postcard is a marketing piece that stakeholders can provide to interested parties; it will guide them to the economic development benefits section on the Wind Powering America website.

  20. Offshore Wind Geoff Sharples

    E-Print Network [OSTI]

    Kammen, Daniel M.

    Offshore Wind Geoff Sharples geoff@clearpathenergyllc.com #12;Frequently Unanswered Ques?ons · Why don't "they" build more offshore wind? · Why not make States Cape Wind PPA at 18 c/kWh #12;The cycle of non-innova?on Offshore

  1. Wind power outlook 2006

    SciTech Connect (OSTI)

    anon.

    2006-04-15

    This annual brochure provides the American Wind Energy Association's up-to-date assessment of the wind industry in the United States. This 2006 general assessment shows positive signs of growth, use and acceptance of wind energy as a vital component of the U.S. energy mix.

  2. LIDAR Wind Speed Measurement Analysis and Feed-Forward Blade Pitch Control for Load Mitigation in Wind Turbines: January 2010--January 2011

    SciTech Connect (OSTI)

    Dunne, F.; Simley, E.; Pao, L.Y.

    2011-10-01

    This report examines the accuracy of measurements that rely on Doppler LIDAR systems to determine their applicability to wind turbine feed-forward control systems and discusses feed-forward control system designs that use preview wind measurements. Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feed-forward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. The first half of this report examines the accuracy of different measurement scenarios that rely on coherent continuous-wave or pulsed Doppler LIDAR systems to determine their applicability to feed-forward control. In particular, the impacts of measurement range and angular offset from the wind direction are studied for various wind conditions. A realistic case involving a scanning LIDAR unit mounted in the spinner of a wind turbine is studied in depth with emphasis on choices for scan radius and preview distance. The effects of turbulence parameters on measurement accuracy are studied as well. Continuous-wave and pulsed LIDAR models based on typical commercially available units were used in the studies present in this report. The second half of this report discusses feed-forward control system designs that use preview wind measurements. Combined feedback/feed-forward blade pitch control is compared to industry standard feedback control when simulated in realistic turbulent above-rated winds. The feed-forward controllers are designed to reduce fatigue loads, increasing turbine lifetime and therefore reducing the cost of energy. Three feed-forward designs are studied: non-causal series expansion, Preview Control, and optimized FIR filter. The input to the feed-forward controller is a measurement of incoming wind speeds that could be provided by LIDAR. Non-causal series expansion and Preview Control methods reduce blade root loads but increase tower bending in simulation results. The optimized FIR filter reduces loads overall, keeps pitch rates low, and maintains rotor speed regulation and power capture, while using imperfect wind measurements provided by the spinning continuous-wave LIDAR model.

  3. Why do meteorologists use wind vanes? Wind vanes are used to determine the direction of the wind. Wind

    E-Print Network [OSTI]

    Nebraska-Lincoln, University of

    Fun Facts Why do meteorologists use wind vanes? Wind vanes are used to determine the direction of the wind. Wind· vanes are also called weather vanes. What do wind vanes look like on a weather station? Wind vanes that are on weather stations look a lot like the one you· made! The biggest differences

  4. Improved detection of atmospheric turbulence with SLODAR

    E-Print Network [OSTI]

    Michael Goodwin; Charles Jenkins; Andrew Lambert

    2007-06-19

    We discuss several improvements in the detection of atmospheric turbulence using SLOpe Detection And Ranging (SLODAR). Frequently, SLODAR observations have shown strong ground-layer turbulence, which is beneficial to adaptive optics. We show that current methods which neglect atmospheric propagation effects can underestimate the strength of high altitude turbulence by up to ~ 30%. We show that mirror and dome seeing turbulence can be a significant fraction of measured ground-layer turbulence, some cases up to ~ 50%. We also demonstrate a novel technique to improve the nominal height resolution, by a factor of 3, called Generalized SLODAR. This can be applied when sampling high-altitude turbulence, where the nominal height resolution is the poorest, or for resolving details in the important ground-layer.

  5. Wind energy applications guide

    SciTech Connect (OSTI)

    anon.

    2001-01-01

    The brochure is an introduction to various wind power applications for locations with underdeveloped transmission systems, from remote water pumping to village electrification. It includes an introductory section on wind energy, including wind power basics and system components and then provides examples of applications, including water pumping, stand-alone systems for home and business, systems for community centers, schools, and health clinics, and examples in the industrial area. There is also a page of contacts, plus two specific example applications for a wind-diesel system for a remote station in Antarctica and one on wind-diesel village electrification in Russia.

  6. Wave turbulence buildup in a vibrating plate

    E-Print Network [OSTI]

    Auliel, Maria Ines; Mordant, Nicolas

    2015-01-01

    We report experimental and numerical results on the buildup of the energy spectrum in wave turbulence of a vibrating thin elastic plate. Three steps are observed: first a short linear stage, then the turbulent spectrum is constructed by the propagation of a front in wave number space and finally a long time saturation due to the action of dissipation. The propagation of a front at the second step is compatible with scaling predictions from the Weak Turbulence Theory.

  7. Large-Eddy Simulation of Wind-Plant Aerodynamics: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Lee, S.; Moriarty, P. J.; Martinez, L. A.; Leonardi, S.; Vijayakumar, G.; Brasseur, J. G.

    2012-01-01

    In this work, we present results of a large-eddy simulation of the 48 multi-megawatt turbines composing the Lillgrund wind plant. Turbulent inflow wind is created by performing an atmospheric boundary layer precursor simulation and turbines are modeled using a rotating, variable-speed actuator line representation. The motivation for this work is that few others have done wind plant large-eddy simulations with a substantial number of turbines, and the methods for carrying out the simulations are varied. We wish to draw upon the strengths of the existing simulations and our growing atmospheric large-eddy simulation capability to create a sound methodology for performing this type of simulation. We have used the OpenFOAM CFD toolbox to create our solver.

  8. A concurrent precursor inflow method for Large Eddy Simulations and applications to finite length wind farms

    E-Print Network [OSTI]

    Stevens, Richard J A M; Meneveau, Charles

    2014-01-01

    In order to enable simulations of developing wind turbine array boundary layers with highly realistic inflow conditions a concurrent precursor method for Large Eddy Simulations is proposed. In this method we consider two domains simultaneously, i.e. in one domain a turbulent Atmospheric Boundary Layer (ABL) without wind turbines is simulated in order to generate the turbulent inflow conditions for a second domain in which the wind turbines are placed. The benefit of this approach is that a) it avoids the need for large databases in which the turbulent inflow conditions are stored and the correspondingly slow I/O operations and b) we are sure that the simulations are not negatively affected by statically swept fixed inflow fields or synthetic fields lacking the proper ABL coherent structures. Sample applications are presented, in which, in agreement with field data a strong decrease of the power output of downstream wind-turbines with respect to the first row of wind-turbines is observed for perfectly aligned ...

  9. Thermal Wind The thermal wind is defined as the vector difference between the geostrophic winds at

    E-Print Network [OSTI]

    Hennon, Christopher C.

    ATMS 310 Thermal Wind The thermal wind is defined as the vector difference between the geostrophic winds at two levels. It is not really a wind at all, just a measure of the shear of the geostrophic wind. But there are good reasons for considering the geostrophic wind; mainly, it provides a convenient way of connecting

  10. Flame Surface Fractal Characteristics in Premixed Turbulent Combustion at High Turbulence Intensities

    E-Print Network [OSTI]

    Gülder, Ömer L.

    Flame Surface Fractal Characteristics in Premixed Turbulent Combustion at High Turbulence of the flame surfaces in premixed turbulent combustion, the fractal approach is considered to be one with diameters of 11.2 and 22.4 mm, with flames of propane­air with equivalence ratios of 0.8 and 1

  11. Accessing Online COR Training

    Office of Energy Efficiency and Renewable Energy (EERE)

    Contracting Officer’s Representative (COR) training is now be available in an online format. "Accessing Online COR Training" provides a step-by-step guide to access the online COR course. 

  12. The Origin of Molecular Cloud Turbulence

    E-Print Network [OSTI]

    Padoan, Paolo; Haugboelle, Troels; Nordlund, Ake

    2015-01-01

    Turbulence is ubiquitous in molecular clouds (MCs), but its origin is still unclear because MCs are usually assumed to live longer than the turbulence dissipation time. It has been shown that interstellar medium (ISM) turbulence is likely driven by SN explosions, but it has never been demonstrated that SN explosions can establish and maintain a turbulent cascade inside MCs consistent with the observations. In this work, we carry out a simulation of SN-driven turbulence in a volume of (250 pc)^3, specifically designed to test if SN driving alone can be responsible for the observed turbulence inside MCs. We find that SN driving establishes velocity scaling consistent with the usual scaling laws of supersonic turbulence. This also means that previous idealized simulations of MC turbulence, driven with a random, large-scale volume force, were correctly adopted as appropriate models for MC turbulence, despite the artificial driving. We also find the same scaling laws extend to the interior of MCs, and their normal...

  13. National Wind Distance Learning Collaborative

    SciTech Connect (OSTI)

    Dr. James B. Beddow

    2013-03-29

    Executive Summary The energy development assumptions identified in the Department of Energy's position paper, 20% Wind Energy by 2030, projected an exploding demand for wind energy-related workforce development. These primary assumptions drove a secondary set of assumptions that early stage wind industry workforce development and training paradigms would need to undergo significant change if the workforce needs were to be met. The current training practice and culture within the wind industry is driven by a relatively small number of experts with deep field experience and knowledge. The current training methodology is dominated by face-to-face, classroom based, instructor present training. Given these assumptions and learning paradigms, the purpose of the National Wind Distance Learning Collaborative was to determine the feasibility of developing online learning strategies and products focused on training wind technicians. The initial project scope centered on (1) identifying resources that would be needed for development of subject matter and course design/delivery strategies for industry-based (non-academic) training, and (2) development of an appropriate Learning Management System (LMS). As the project unfolded, the initial scope was expanded to include development of learning products and the addition of an academic-based training partner. The core partners included two training entities, industry-based Airstreams Renewables and academic-based Lake Area Technical Institute. A third partner, Vision Video Interactive, Inc. provided technology-based learning platforms (hardware and software). The revised scope yielded an expanded set of results beyond the initial expectation. Eight learning modules were developed for the industry-based Electrical Safety course. These modules were subsequently redesigned and repurposed for test application in an academic setting. Software and hardware developments during the project's timeframe enabled redesign providing for student access through the use of tablet devices such as iPads. Early prototype Learning Management Systems (LMS) featuring more student-centric access and interfaces with emerging social media were developed and utilized during the testing applications. The project also produced soft results involving cross learning between and among the partners regarding subject matter expertise, online learning pedagogy, and eLearning technology-based platforms. The partners believe that the most significant, overarching accomplishment of the project was the development and implementation of goals, activities, and outcomes that significantly exceeded those proposed in the initial grant application submitted in 2009. Key specific accomplishments include: (1) development of a set of 8 online learning modules addressing electrical safety as it relates to the work of wind technicians; (3) development of a flexible, open-ended Learning Management System (LMS): (3) creation of a robust body of learning (knowledge, experience, skills, and relationships). Project leaders have concluded that there is substantial resource equity that could be leverage and recommend that it be carried forward to pursue a Next Stage Opportunity relating to development of an online core curriculum for institute and community college energy workforce development programs.

  14. Turbulent Supersonic Channel Flow: Direct Numerical Simulation and Modeling

    E-Print Network [OSTI]

    Heinz, Stefan

    modeling: the turbulence frequency production mechanism, wall damping effects on turbulence model frequency production mechanisms and wall damping effects may be explained very well on the basis, Chik w = wall viscosity = kinematic viscosity, = T = turbulent kinematic viscosity, Ck d = pressure

  15. Wind energy conversion system

    DOE Patents [OSTI]

    Longrigg, Paul (Golden, CO)

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  16. Wind tower service lift

    DOE Patents [OSTI]

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  17. THIRD MOMENTS AND THE ROLE OF ANISOTROPY FROM VELOCITY SHEAR IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Stawarz, Joshua E.; Vasquez, Bernard J.; Smith, Charles W.; Forman, Miriam A.; Klewicki, Joseph E-mail: Bernie.Vasquez@unh.edu E-mail: Miriam.Forman@sunysb.edu

    2011-07-20

    We have extended the recent analyses of magnetohydrodynamic third moments as they relate to the turbulent energy cascade in the solar wind to consider the effects of large-scale shear flows. Moments from a large set of Advanced Composition Explorer data have been taken, and chosen data intervals are characterized by the rate of change in the solar wind speed. Mean dissipation rates are obtained in accordance with the predictions of homogeneous shear-driven turbulence. Agreement with predictions is best made for rarefaction intervals where the solar wind speed is decreasing with time. For decreasing speed intervals, we find that the dissipation rates increase with increasing shear magnitude and that the shear-induced fluctuation anisotropy is consistent with a relatively small amount.

  18. Anomalous Viscosity, Resistivity, and Thermal Diffusivity of the Solar Wind Plasma

    E-Print Network [OSTI]

    Mahendra K. Verma

    1995-09-05

    In this paper we have estimated typical anomalous viscosity, resistivity, and thermal difffusivity of the solar wind plasma. Since the solar wind is collsionless plasma, we have assumed that the dissipation in the solar wind occurs at proton gyro radius through wave-particle interactions. Using this dissipation length-scale and the dissipation rates calculated using MHD turbulence phenomenology [{\\it Verma et al.}, 1995a], we estimate the viscosity and proton thermal diffusivity. The resistivity and electron's thermal diffusivity have also been estimated. We find that all our transport quantities are several orders of magnitude higher than those calculated earlier using classical transport theories of {\\it Braginskii}. In this paper we have also estimated the eddy turbulent viscosity.

  19. Wind turbine having a direct-drive drivetrain

    DOE Patents [OSTI]

    Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

    2008-10-07

    A wind turbine (100) comprising an electrical generator (108) that includes a rotor assembly (112). A wind rotor (104) that includes a wind rotor hub (124) is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle (160) via a bearing assembly (180). The wind rotor hub includes an opening (244) having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity (380) inside the wind rotor hub. The spindle is attached to a turret (140) supported by a tower (136). Each of the spindle, turret and tower has an interior cavity (172, 176, 368) that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system (276) for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  20. ASCR Workshop on Turbulent Flow Simulations at the Exascale:...

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

    ASCR Workshop on Turbulent Flow Simulations at the Exascale: Opportunities and Challenges ASCR Workshop on Turbulent Flow Simulations at the Exascale: Opportunities and Challenges...

  1. Turbulence-Flame Interactions in Type Ia Supernovae

    E-Print Network [OSTI]

    Aspden, Andrew J; Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 50A-1148, Berkeley, CA 94720 (Authors 1, 2 & 3); Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (Author 4); Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (Author 5)

    2008-01-01

    dynamics of turbulent thermonuclear ?ames are essential tostudy of turbulent thermonuclear ? ames that explores aadapted to the study of thermonuclear ?ames, as described in

  2. Assessment of Combustion and Turbulence Models for the Simulation...

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

    Combustion and Turbulence Models for the Simulation of Combustion Processes in a DI Diesel Engine Assessment of Combustion and Turbulence Models for the Simulation of Combustion...

  3. Can we characterize turbulence in premixed flames?

    SciTech Connect (OSTI)

    Lipatnikov, A.N. [Department of Applied Mechanics, Chalmers University of Technology, Gothenburg, 412 96 (Sweden)

    2009-06-15

    Modeling of premixed turbulent combustion involves averaging reaction rates in turbulent flows. The focus of most approaches to resolving this problem has been placed on determining the dependence of the mean rate w of product creation on the laminar flame speed S{sub L}, the rms turbulence velocity u', etc. The goal of the present work is to draw attention to another issue: May the input quantity u{sup '} for a model of w= w(u'/S{sub L},..) be considered to be known? The point is that heat release substantially affects turbulence and, hence, turbulence characteristics in premixed flames should be modeled. However, standard moment methods for numerically simulating turbulent flows do not allow us to evaluate the true turbulence characteristics in a flame. For instance, the Reynolds stresses in premixed flames are affected not only by turbulence itself, but also by velocity jump across flamelets. A common way to resolving this problem consists of considering the Reynolds stresses conditioned on unburned (or burned) mixture to be the true turbulence characteristics. In the present paper, this widely accepted but never proved hypothesis is put into question, first, by considering simple model constant-density problems (flame motion in an oscillating one-dimensional laminar flow; flame stabilized in a periodic shear, one-dimensional, laminar flow; turbulent mixing). In all the cases, the magnitude of velocity fluctuations, calculated using the conditioned Reynolds stresses, is affected by the intermittency of reactants and products and, hence, is not the true rms velocity. Second, the above claim is further supported by comparing balance equations for the mean and conditioned Reynolds stresses. The conditioned Reynolds stresses do not characterize the true turbulence in flames, because conditional averaging cuts off flow regions characterized by either high or low velocities. (author)

  4. Energy Department Announces Funding to Access Higher Quality Wind Resources

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergy A plug-inPPL EnergyPlus,DepartmentFederalJuly 8, 2015inSolarWinners | Departmentand

  5. Solar/Wind Access Policy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS ReportEurope GmbH JumpSloughInfra Inc

  6. Turbulent electron transport in edge pedestal by electron temperature gradient turbulence

    SciTech Connect (OSTI)

    Singh, R.; Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 ; Jhang, Hogun; Diamond, P. H.; CMTFO and CASS, University of California, San Diego 92093-0424, California

    2013-11-15

    We present a model for turbulent electron thermal transport at the edge pedestal in high (H)-mode plasmas based on electron temperature gradient (ETG) turbulence. A quasi-linear analysis of electrostatic toroidal ETG modes shows that both turbulent electron thermal diffusivity and hyper-resistivity exhibits the Ohkawa scaling in which the radial correlation length of turbulence becomes the order of electron skin depth. Combination of the Ohkawa scales and the plasma current dependence results in a novel confinement scaling inside the pedestal region. It is also shown that ETG turbulence induces a thermoelectric pinch, which may accelerate the density pedestal formation.

  7. Taylor-Couette turbulence at radius ratio $\\eta=0.5$: scaling, flow structures and plumes

    E-Print Network [OSTI]

    van der Veen, Roeland C A; Merbold, Sebastian; Harlander, Uwe; Egbers, Christoph; Lohse, Detlef; Sun, Chao

    2015-01-01

    Using high-resolution particle image velocimetry we measure velocity profiles, the wind Reynolds number and characteristics of turbulent plumes in Taylor-Couette flow for a radius ratio of 0.5 and Taylor number of up to $6.2\\cdot10^9$. The extracted angular velocity profiles follow a log-law more closely than the azimuthal velocity profiles due to the strong curvature of this $\\eta=0.5$ setup. The scaling of the wind Reynolds number with the Taylor number agrees with the theoretically predicted 3/7-scaling for the classical turbulent regime, which is much more pronounced than for the well-explored $\\eta=0.71$ case, for which the ultimate regime sets in at much lower Ta. By measuring at varying axial positions, roll structures are found for counter-rotation while no clear coherent structures are seen for pure inner cylinder rotation. In addition, turbulent plumes coming from the inner and outer cylinder are investigated. For pure inner cylinder rotation, the plumes in the radial velocity move away from the inn...

  8. Regulation of Solar WindMagnetosphere Coupling by Ionospheric Outflows William Lotko, PI for Dartmouth College

    E-Print Network [OSTI]

    Lotko, William

    potential are also reduced, as is the flux of outflowing ionospheric ions, access of solar wind plasmaRegulation of Solar Wind­Magnetosphere Coupling by Ionospheric Outflows William Lotko, PI blunted as shown in the figure 2, which compares proton densities at 1634 UT in global simulations

  9. Sandia Energy - Applied Turbulent Combustion

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

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

  10. Stochastic models for turbulent reacting flows

    SciTech Connect (OSTI)

    Kerstein, A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.

  11. Turbulence of a Unidirectional Flow Bjorn Birnir

    E-Print Network [OSTI]

    Birnir, Björn

    -flying aircraft. Turbulent drag also prevents the design of more fuel-efficient cars and aircrafts. Turbulence plays a role in the heat trans- fer in nuclear reactors, causes drag in oil pipelines and influence and intrigued people for centuries. Five centuries ago a fluid engineer by the name of Leonardo da Vinci tackled

  12. Fifteen Lectures on Laminar and Turbulent Combustion

    E-Print Network [OSTI]

    Peters, Norbert

    Fifteen Lectures on Laminar and Turbulent Combustion N. Peters RWTH Aachen Ercoftac Summer School in Combustion Systems 1 Lecture 2: Calculation of Adiabatic Flame Temperatures and Chemical Equilibria 20: Laminar Diffusion Flames: Different Flow Geometries 156 Lecture 11: Turbulent Combustion: Introduction

  13. Gansu Xinhui Wind Power | Open Energy Information

    Open Energy Info (EERE)

    Xinhui Wind Power Jump to: navigation, search Name: Gansu Xinhui Wind Power Place: China Sector: Wind energy Product: China-based joint venture engaged in developing wind projects....

  14. Wind Tunnel Building - 3 

    E-Print Network [OSTI]

    Unknown

    2005-06-30

    1 Energy Systems Laboratory 1 A METHODOLOGY FOR CALCULATING EMISSIONS REDUCTIONS FROM RENEWABLE ENERGY PROGRAMS AND ITS APPLICATION TO THE WIND FARMS IN THE TEXAS ERCOT REGION Zi Liu, Jeff Haberl, Juan-Carlos Baltazar, Kris Subbarao, Charles... on Sweetwater I Wind Farm Capacity Factor Analysis Application to All Wind Farms Uncertainty Analysis Emissions Reduction Summary Energy Systems Laboratory 3 SUMMARYEMISSIONS REDUCTION UNCERTAINTY ANALYSIS APPLICATIONMETHODOLOGYINTRODUCTION Background...

  15. Meso-scale turbulence in living fluids

    E-Print Network [OSTI]

    Wensink, Henricus H; Heidenreich, Sebastian; Drescher, Knut; Goldstein, Raymond E; Löwen, Hartmut; Yeomans, Julia M

    2012-01-01

    Turbulence is ubiquitous, from oceanic currents to small-scale biological and quantum systems. Self-sustained turbulent motion in microbial suspensions presents an intriguing example of collective dynamical behavior amongst the simplest forms of life, and is important for fluid mixing and molecular transport on the microscale. The mathematical characterization of turbulence phenomena in active non-equilibrium fluids proves even more difficult than for conventional liquids or gases. It is not known which features of turbulent phases in living matter are universal or system-specific, or which generalizations of the Navier-Stokes equations are able to describe them adequately. Here, we combine experiments, particle simulations, and continuum theory to identify the statistical properties of self-sustained meso-scale turbulence in active systems. To study how dimensionality and boundary conditions affect collective bacterial dynamics, we measured energy spectra and structure functions in dense Bacillus subtilis su...

  16. Proceedings Nordic Wind Power Conference

    E-Print Network [OSTI]

    Estimation of Possible Power for Wind Plant Control Power Fluctuations from Offshore Wind Farms; Model Validation System grounding of wind farm medium voltage cable grids Faults in the Collection Grid of Offshore systems of wind turbines and wind farms. NWPC presents the newest research results related to technical

  17. Wind Energy and Spatial Technology

    E-Print Network [OSTI]

    Schweik, Charles M.

    2/3/2011 1 Wind Energy and Spatial Technology Lori Pelech Why Wind Energy? A clean, renewable 2,600 tons of carbon emissions annually ­ The economy · Approximately 85,000 wind energy workers to Construct a Wind Farm... Geo-Spatial Components of Wind Farm Development Process Selecting a Project Site

  18. Module Handbook Specialisation Wind Energy

    E-Print Network [OSTI]

    Habel, Annegret

    Module Handbook Specialisation Wind Energy 2nd Semester for the Master Programme REMA/EUREC Course 2008/2009 NTU Athens Specialisation Provider: Wind Energy #12;Specialisation Wind Energy, NTU Athens, 2nd Semester Module 1/Wind Energy: Wind potential, Aerodynamics & Loading

  19. Wind Engineering & Natural Disaster Mitigation

    E-Print Network [OSTI]

    Lennard, William N.

    Wind Engineering & Natural Disaster Mitigation For more than 45 years, Western University has been internationally recognized as the leading university for wind engineering and wind- related research. Its of environmental disaster mitigation, with specific strengths in wind and earthquake research. Boundary Layer Wind

  20. Accelerating Offshore Wind Development

    Broader source: Energy.gov [DOE]

    Today the Energy Department announced investments in seven offshore wind demonstration projects. Check out our map to see where these projects will be located.

  1. Wind/Water Nexus

    SciTech Connect (OSTI)

    Not Available

    2006-04-01

    Nobel laureate Richard Smalley cited energy and water as among humanity's top problems for the next 50 years as the world's population increases from 6.3 billion to 9 billion. The U.S. Department of Energy's Wind and Hydropower Program has initiated an effort to explore wind energy's role as a technical solution to this critically important issue in the United States and the world. This four-page fact sheet outlines five areas in which wind energy can contribute: thermoelectric power plant/water processes, irrigation, municipal water supply, desalination, and wind/hydropower integration.

  2. Vertical axis wind turbines

    DOE Patents [OSTI]

    Krivcov, Vladimir (Miass, RU); Krivospitski, Vladimir (Miass, RU); Maksimov, Vasili (Miass, RU); Halstead, Richard (Rohnert Park, CA); Grahov, Jurij (Miass, RU)

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  3. Talkin’ Bout Wind Generation

    Office of Energy Efficiency and Renewable Energy (EERE)

    The amount of electricity generated by the wind industry started to grow back around 1999, and since 2007 has been increasing at a rapid pace.

  4. ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Rha, Kicheol; Ryu, Chang-Mo [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)] [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Yoon, Peter H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)] [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)

    2013-09-20

    A plausible mechanism responsible for producing asymmetric electron velocity distribution functions in the solar wind is investigated by means of one-dimensional electrostatic particle-in-cell (PIC) simulation. A recent paper suggests that the variation in the ion-to-electron temperature ratio influences the nonlinear wave-particle dynamics such that it results in the formation of asymmetric distributions. The present PIC code simulation largely confirms this finding, but quantitative differences between the weak turbulence formalism and the present PIC simulation are also found, suggesting the limitation of the analytical method. The inter-relationship between the asymmetric electron distribution and the ion-to-electron temperature ratio may be a new useful concept for the observation.

  5. Wind turbine/generator set having a stator cooling system located between stator frame and active coils

    DOE Patents [OSTI]

    Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

    2012-11-13

    A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  6. DOE Offers Conditional Commitment to Cape Wind Offshore Wind...

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

    step toward issuing a 150 million loan guarantee to support the construction of the Cape Wind offshore wind project with a conditional commitment to Cape Wind Associates, LLC. The...

  7. Wind Power Today, 2010, Wind and Water Power Program (WWPP)

    SciTech Connect (OSTI)

    Not Available

    2010-05-01

    Wind Power Today is an annual publication that provides an overview of the wind energy research conducted by the U.S. Department of Energy Wind and Water Power Program.

  8. Wind Powering America's Wind for Schools Team Honored with Wirth...

    Office of Environmental Management (EM)

    Powering America's Wind for Schools Team Honored with Wirth Chair Award Wind Powering America's Wind for Schools Team Honored with Wirth Chair Award May 1, 2012 - 2:46pm Addthis...

  9. A comparison of weak-turbulence and particle-in-cell simulations of weak electron-beam plasma interaction

    SciTech Connect (OSTI)

    Ratcliffe, H. Brady, C. S.; Che Rozenan, M. B.; Nakariakov, V. M.

    2014-12-15

    Quasilinear theory has long been used to treat the problem of a weak electron beam interacting with plasma and generating Langmuir waves. Its extension to weak-turbulence theory treats resonant interactions of these Langmuir waves with other plasma wave modes, in particular, ion-sound waves. These are strongly damped in plasma of equal ion and electron temperatures, as sometimes seen in, for example, the solar corona and wind. Weak turbulence theory is derived in the weak damping limit, with a term describing ion-sound wave damping then added. In this paper, we use the EPOCH particle-in-cell code to numerically test weak turbulence theory for a range of electron-ion temperature ratios. We find that in the cold ion limit, the results agree well, but for increasing ion temperature the three-wave resonance becomes broadened in proportion to the ion-sound wave damping rate. Additionally, we establish lower limits on the number of simulation particles needed to accurately reproduce the electron and wave distributions in their saturated states and to reproduce their intermediate states and time evolution. These results should be taken into consideration in, for example, simulations of plasma wave generation in the solar corona of Type III solar radio bursts from the corona to the solar wind and in weak turbulence investigations of ion-acoustic lines in the ionosphere.

  10. Twisted photon entanglement through turbulent air across Vienna

    E-Print Network [OSTI]

    Mario Krenn; Johannes Handsteiner; Matthias Fink; Robert Fickler; Anton Zeilinger

    2015-07-23

    Photons with a twisted phase front can carry a discrete, in principle unbounded amount of orbital angular momentum (OAM). The large state space allows for complex types of entanglement, interesting both for quantum communication and for fundamental tests of quantum theory. However, the distribution of such entangled states over large distances was thought to be infeasible due to influence of atmospheric turbulence, indicating a serious limitation on their usefulness. Here we show that it is possible to distribute quantum entanglement encoded in OAM over a turbulent intra-city link of 3 kilometers. We confirm quantum entanglement of the first two higher-order levels (with OAM=$\\pm 1 \\hbar$ and $\\pm 2 \\hbar$). They correspond to four new quantum channels orthogonal to all that have been used in long-distance quantum experiments so far. Therefore a promising application would be quantum communication with a large alphabet. We also demonstrate that our link allows access to up to 11 quantum channels of OAM. The restrictive factors towards higher numbers are technical limitations that can be circumvented with readily available technologies.

  11. Coupled Mesoscale-Large-Eddy Modeling of Realistic Stable Boundary Layer Turbulence

    E-Print Network [OSTI]

    Wang, Yao; Manuel, Lance

    2013-01-01

    Site-specific flow and turbulence information are needed for various practical applications, ranging from aerodynamic/aeroelastic modeling for wind turbine design to optical diffraction calculations. Even though highly desirable, collecting on-site meteorological measurements can be an expensive, time-consuming, and sometimes a challenging task. In this work, we propose a coupled mesoscale-large-eddy modeling framework to synthetically generate site-specific flow and turbulence data. The workhorses behind our framework are a state-of-the-art, open-source atmospheric model called the Weather Research and Forecasting (WRF) model and a tuning-free large-eddy simulation (LES) model. Using this coupled framework, we simulate a nighttime stable boundary layer (SBL) case from the well-known CASES-99 field campaign. One of the unique aspects of this work is the usage of a diverse range of observations for characterization and validation. The coupled models reproduce certain characteristics of observed low-level jets....

  12. Simultaneous temperature and velocity Lagrangian measurements in turbulent thermal convection

    E-Print Network [OSTI]

    Liot, O; Zonta, F; Chibbaro, S; Coudarchet, T; Gasteuil, Y; Pinton, J -F; Salort, J; Chillà, F

    2015-01-01

    We report joint Lagrangian velocity and temperature measurements in turbulent thermal convection. Measurements are performed using an improved version (extended autonomy) of the neutrally-buoyant instrumented particle that was used by to performed experiments in a parallelepipedic Rayleigh-Benard cell. The temperature signal is obtained from a RFtransmitter. Simultaneously, we determine particle's position and velocity with one camera, which grants access to the Lagrangian heat flux. Due to the extended autonomy of the present particle, we obtain well converged temperature and velocity statistics, as well as pseudo-eulerian maps of velocity and heat flux. Present experimental results have also been compared with the results obtained by a corresponding campaign of Direct Numerical Simulations and Lagrangian Tracking of massless tracers. The comparison between experimental and numerical results show the accuracy and reliability of our experimental measurements. Finally, the analysis of lagrangian velocity and t...

  13. Community Wind Handbook/Understand Your Wind Resource and Conduct...

    Open Energy Info (EERE)

    Help Apps Datasets Community Login | Sign Up Search Page Edit History Community Wind HandbookUnderstand Your Wind Resource and Conduct a Preliminary Estimate < Community...

  14. American Wind Energy Association Wind Energy Finance and Investment Seminar

    Office of Energy Efficiency and Renewable Energy (EERE)

    The American Wind Energy Association Wind Energy Finance and Investment Seminar will be attended by representatives in the financial sector, businesses, bankers, government and other nonprofit...

  15. Public Acceptance of Wind: Foundational Study Near US Wind Facilities

    Wind Powering America (EERE)

    Group * Energy Analysis and Environmental Impacts Department Public Acceptance of Wind Power Ben Hoen Lawrence Berkeley National Laboratory WindExchange Webinar June 17, 2015...

  16. 20% Wind Energy by 2030: Increasing Wind Energy's Contribution...

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

    Supply (Executive Summary) 20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply (Executive Summary) Executive summary of a report on the...

  17. Plasma Turbulence Simulations Reveal Promising Insight for Fusion Energy |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeeding access| DepartmentPeerFederal FleetUpSmall WindPrincetonPlasma

  18. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    al. 2010. Large-scale Offshore Wind for the United States:examined land-based and offshore wind energy in the Easternassistance with the offshore wind energy discussion; Donna

  19. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    with the section on offshore wind; Donna Heimiller and Billythe end of 2011, global offshore wind power capacity stoodEnergy's investments in offshore wind R&D. Interest exists

  20. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    al. 2010. Large-scale Offshore Wind for the United States:assistance with the offshore wind energy discussion; DonnaTechnologies Market Report Offshore Wind Power Project and

  1. Wind Farms in North America

    E-Print Network [OSTI]

    Hoen, Ben

    2014-01-01

    Economic Analysis of a Wind Farm in Nantucket Sound. BeaconP. and Mueller, A. (2010) Wind Farm Announcements and RuralProposed Rail Splitter Wind Farm. Prepared for Hinshaw &

  2. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    Public Service Wind Integration Cost Impact Study. Preparedused to estimate wind integration costs and the ability toColorado 2 GW and 3 GW Wind Integration Cost Study. Denver,

  3. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    from Canada and Mexico; unlike for wind-powered generatingHonduras (16%), Mexico (8%), and Canada (8%). Wind turbineWind belt states include Colorado, Iowa, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico,

  4. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    balancing areas, the use of wind forecasts, and intra-hourchallenges and costs. Wind forecasts are most accurate andare the cost of day-ahead wind forecast error; the remaining

  5. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    of wind power capacity in that state) because generatorsgenerators to provide the needed flexibility to integrate wind power.wind power forecasts by system operators can significantly reduce integration challenges and costs. Intra-hour transmission scheduling and generator

  6. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    AWEA). 2010b. AWEA Small Wind Turbine Global Market Survey,html David, A. 2009. Wind Turbines: Industry and Tradewhich new large-scale wind turbines were installed in 2009 (

  7. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    AWEA’s Wind Energy Weekly, DOE/EPRI’s Turbine Verification10% Wind Energy Penetration New large-scale 10 wind turbineswind energy became more challenging, orders for new turbines

  8. Fort Carson Wind Resource Assessment

    SciTech Connect (OSTI)

    Robichaud, R.

    2012-10-01

    This report focuses on the wind resource assessment, the estimated energy production of wind turbines, and economic potential of a wind turbine project on a ridge in the southeastern portion of the Fort Carson Army base.

  9. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    AWEA). 2010b. AWEA Small Wind Turbine Global Market Survey,a brief discussion on Small Wind Turbines is provided on2010a) sometimes also includes small wind turbines. Other

  10. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    Associates. 2010. SPP WITF Wind Integration Study. LittlePool. David, A. 2011. U.S. Wind Turbine Trade in a Changing2011. David, A. 2010. Impact of Wind Energy Installations on

  11. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01

    ET2/TL-08-1474. May 19, 2010 Wind Technologies Market ReportAssociates. 2010. SPP WITF Wind Integration Study. Little10, 2010. David, A. 2009. Wind Turbines: Industry and Trade

  12. Remote sensing for wind power potential: a prospector's handbook

    SciTech Connect (OSTI)

    Wade, J.E.; Maule, P.A.; Bodvarsson, G.; Rosenfeld, C.L.; Woolley, S.G.; McClenahan, M.R.

    1983-02-01

    Remote sensing can aid in identifying and locating indicators of wind power potential from the terrestrial, marine, and atmospheric environments (i.e.: wind-deformed trees, white caps, and areas of thermal flux). It is not considered as a tool for determining wind power potential. A wide variety of remotely sensed evidence is described in terms of the scale at which evidence of wind power can be identified, and the appropriate remote sensors for finding such evidence. Remote sensing can be used for regional area prospecting using small-scale imagery. The information from such small-scale imagery is most often qualitative, and if it is transitory, examination of a number of images to verify presistence of the feature may be required. However, this evidence will allow rapid screening of a large area. Medium-scale imagery provides a better picture of the evidence obtained from small-scale imagery. At this level it is best to use existing imagery. Criteria relating to land use, accessibility, and proximity of candidate sites to nearby transmission lines can also be effectively evaluated from medium-scale imagery. Large-scale imagery provides the most quantitative evidence of the strength of wind. Wind-deformed trees can be identified at a large number of sites using only a few hours in locally chartered aircraft. A handheld 35mm camera can adequately document any evidence of wind. Three case studies that employ remote sensing prospecting techniques are described. Based on remotely sensed evidence, the wind power potential in three geographically and climatically diverse areas of the United States is estimated, and the estimates are compared to actual wind data in those regions. In addition, the cost of each survey is discussed. The results indicate that remote sensing for wind power potential is a quick, cost effective, and fairly reliable method for screening large areas for wind power potential.

  13. Turbulence

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

    to the major radius were measured using the recently upgraded phase-contrast imaging (PCI) diagnostic 4. The 32 vertical chords of the PCI system (see Fig. 1 (a)) enables the...

  14. NREL: Wind Research - Offshore Wind Resource Characterization

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines lightGeospatialDevelopment of Marine andDrivetrainsNew WindDesign ToolsWind

  15. Diablo Winds Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower VenturesInformation9)ask queries TypeDeveloper|Winds Wind Farm Jump

  16. NREL: Wind Research - Wind Resource Assessment

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework usesofPublications The NREL wind research programWebmaster PleaseWind

  17. Wind Program Accomplishments

    SciTech Connect (OSTI)

    Wind Program

    2012-05-24

    This fact sheet describes some of the accomplishments of DOE's Wind Program through its investments in technology development and market barrier reduction, and how those accomplishments are supporting the advancement of renewable energy generated using the United States' abundant wind resources.

  18. Small Wind Information (Postcard)

    SciTech Connect (OSTI)

    Not Available

    2011-08-01

    The U.S. Department of Energy's Wind Powering America initiative maintains a website section devoted to information about small wind turbines for homeowners, ranchers, and small businesses. This postcard is a marketing piece that stakeholders can provide to interested parties; it will guide them to this online resource.

  19. Carbon smackdown: wind warriors

    ScienceCinema (OSTI)

    Glen Dahlbacka of the Accelerator & Fusion Research Division and Ryan Wiser of the Environmental Energy Technologies Division are the speakers.

    2010-09-01

    July 16. 2010 carbon smackdown summer lecture: learn how Berkeley Lab scientists are developing wind turbines to be used in an urban setting, as well as analyzing what it will take to increase the adoption of wind energy in the U.S.

  20. Turbulence-chemistry interactions in reacting flows

    SciTech Connect (OSTI)

    Barlow, R.S.; Carter, C.D. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Interactions between turbulence and chemistry in nonpremixed flames are investigated through multiscalar measurements. Simultaneous point measurements of major species, NO, OH, temperature, and mixture fraction are obtained by combining spontaneous Raman scattering, Rayleigh scattering, and laser-induced fluorescence (LIF). NO and OH fluorescence signals are converted to quantitative concentrations by applying shot-to-shot corrections for local variations of the Boltzmann fraction and collisional quenching rate. These measurements of instantaneous thermochemical states in turbulent flames provide insights into the fundamental nature of turbulence-chemistry interactions. The measurements also constitute a unique data base for evaluation and refinement of turbulent combustion models. Experimental work during the past year has focused on three areas: (1) investigation of the effects of differential molecular diffusion in turbulent combustion: (2) experiments on the effects of Halon CF{sub 3}Br, a fire retardant, on the structure of turbulent flames of CH{sub 4} and CO/H{sub 2}/N{sub 2}; and (3) experiments on NO formation in turbulent hydrogen jet flames.

  1. Outflow Driven Turbulence in Molecular Clouds

    E-Print Network [OSTI]

    Jonathan J. Carroll; Adam Frank; Eric G. Blackman; Andrew J. Cunningham; Alice C. Quillen

    2008-05-30

    In this paper we explore the relationship between protostellar outflows and turbulence in molecular clouds. Using 3-D numerical simulations we focus on the hydrodynamics of multiple outflows interacting within a parsec scale volume. We explore the extent to which transient outflows injecting directed energy and momentum into a sub-volume of a molecular cloud can be converted into random turbulent motions. We show that turbulence can readily be sustained by these interactions and show that it is possible to broadly characterize an effective driving scale of the outflows. We compare the velocity spectrum obtained in our studies to that of isotropically forced hydrodynamic turbulence finding that in outflow driven turbulence a power law is indeed achieved. However we find a steeper spectrum (beta ~ 3) is obtained in outflow driven turbulence models than in isotropically forced simulations (beta ~ 2). We discuss possible physical mechanisms responsible for these results as well and their implications for turbulence in molecular clouds where outflows will act in concert with other processes such as gravitational collapse.

  2. Fixed-Speed and Variable-Slip Wind Turbines Providing Spinning Reserves to the Grid: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Singh, M.; Gevorgian, V.

    2012-11-01

    As the level of wind penetration increases, wind turbine technology must move from merely generating power from wind to taking a role in supporting the bulk power system. Wind turbines should have the capability to provide inertial response and primary frequency (governor) response so they can support the frequency stability of the grid. To provide governor response, wind turbines should be able to generate less power than the available wind power and hold the rest in reserve, ready to be accessed as needed. This paper explores several ways to control wind turbine output to enable reserve-holding capability. This paper focuses on fixed-speed (also known as Type 1) and variable-slip (also known as Type 2) turbines.

  3. The T-REX valley wind intercomparison project

    SciTech Connect (OSTI)

    Schmidli, J; Billings, B J; Burton, R; Chow, F K; De Wekker, S; Doyle, J D; Grubisic, V; Holt, T R; Jiang, Q; Lundquist, K A; Ross, A N; Sheridan, P; Vosper, S; Whiteman, C D; Wyszogrodzki, A A; Zaengl, G; Zhong, S

    2008-08-07

    An accurate simulation of the evolution of the atmospheric boundary layer is very important, as the evolution of the boundary layer sets the stage for many weather phenomena, such as deep convection. Over mountain areas the evolution of the boundary layer is particularly complex, due to the nonlinear interaction between boundary layer turbulence and thermally-induced mesoscale wind systems, such as the slope and valley winds. As the horizontal resolution of operational forecasts progresses to finer and finer resolution, more and more of the thermally-induced mesoscale wind systems can be explicitly resolved, and it is very timely to document the current state-of-the-art of mesoscale models at simulating the coupled evolution of the mountain boundary layer and the valley wind system. In this paper we present an intercomparison of valley wind simulations for an idealized valley-plain configuration using eight state-of-the-art mesoscale models with a grid spacing of 1 km. Different sets of three-dimensional simulations are used to explore the effects of varying model dynamical cores and physical parameterizations. This intercomparison project was conducted as part of the Terrain-induced Rotor Experiment (T-REX; Grubisic et al., 2008).

  4. Landmark Report Analyzes Current State of U.S. Offshore Wind Industry (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-09-01

    New report assesses offshore wind industry, offshore wind resource, technology challenges, economics, permitting procedures, and potential risks and benefits. The National Renewable Energy Laboratory (NREL) recently published a new report that analyzes the current state of the offshore wind energy industry, Large-Scale Offshore Wind Power in the United States. It provides a broad understanding of the offshore wind resource, and details the associated technology challenges, economics, permitting procedures, and potential risks and benefits of developing this clean, domestic, renewable resource. The United States possesses large and accessible offshore wind energy resources. The availability of these strong offshore winds close to major U.S. coastal cities significantly reduces power transmission issues. The report estimates that U.S. offshore winds have a gross potential generating capacity four times greater than the nation's present electric capacity. According to the report, developing the offshore wind resource along U.S. coastlines and in the Great Lakes would help the nation: (1) Achieve 20% of its electricity from wind by 2030 - Offshore wind could supply 54 gigawatts of wind capacity to the nation's electrical grid, increasing energy security, reducing air and water pollution, and stimulating the domestic economy. (2) Provide clean power to its coastal demand centers - Wind power emits no carbon dioxide (CO2) and there are plentiful winds off the coasts of 26 states. (3) Revitalize its manufacturing sector - Building 54 GW of offshore wind energy facilities would generate an estimated $200 billion in new economic activity, and create more than 43,000 permanent, well-paid technical jobs in manufacturing, construction, engineering, operations and maintenance. NREL's report concludes that the development of the nation's offshore wind resources can provide many potential benefits, and with effective research, policies, and commitment, offshore wind energy can play a vital role in future U.S. energy markets.

  5. Illinois Wind Workers Group

    SciTech Connect (OSTI)

    David G. Loomis

    2012-05-28

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  6. The spatio-temporal spectrum of turbulent flows

    E-Print Network [OSTI]

    di Leoni, P Clark; Mininni, P D

    2015-01-01

    Identification and extraction of vortical structures and of waves in a disorganized flow is a mayor challegen in the study of turbulence. We present a study of the spatio-temporal behavior of turbulent flows in the presence of different restitutive forces. We show how to compute and analyze the spatio-temporal spectrum from data stemming from numerical simulations and from laboratory experiments. Four cases are considered: homogeneous and isotropic turbulence, rotating turbulence, stratified turbulence, and water wave turbulence. For homogeneous and isotropic turbulence, the spectrum allows identification of random sweeping. For rotating and for stratified turbulence, the spectrum allows identification of the waves, quantification of the energy in the waves and in the turbulent eddies, and identification of physical mechanisms such as Doppler shift and wave absorption in critical layers. Finally, in water wave turbulence the spectrum shows a transition from gravity-capillary waves to bound waves as the amplit...

  7. NREL SBV Pilot Wind Technologies

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

    capabilities to develop everything at one location-from small residential wind turbines and components to utility-scale offshore wind technologies. With the NWTC, partners...

  8. 2012 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2014-01-01

    wind power curtailment and the evolution in turbine design,power and wind resource quality confirms this offsetting effect and shows that turbine design

  9. Maryland Offshore Wind Annual Meeting

    Broader source: Energy.gov [DOE]

    This event will provide updates on regional offshore wind projects and will help attendees understand Maryland's offshore wind project and the team members required. Participants will also learn...

  10. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01

    Policy Landscape Is Now More Favorable to Wind Energy thanPolicy Landscape Is Now More Favorable to Wind Energy than

  11. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    regulation and frequency response services charge for wind energyRegulation and Frequency Response Service that charges a higher rate for wind energy

  12. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01

    electricity demand growth; existing state policies that are insufficient to support future wind power capacity additions at the levels 2011 Wind Technologies Market

  13. 2008 WIND TECHNOLOGIES MARKET REPORT

    E-Print Network [OSTI]

    Bolinger, Mark

    2010-01-01

    Lab staff. Wind Project Operations and Maintenance CostsWind project operations and maintenance costs come primarilyEnergy Laboratory operations and maintenance publicly owned

  14. Wind Fins: Novel Lower-Cost Wind Power System

    SciTech Connect (OSTI)

    David C. Morris; Dr. Will D. Swearingen

    2007-10-08

    This project evaluated the technical feasibility of converting energy from the wind with a novel “wind fin” approach. This patent-pending technology has three major components: (1) a mast, (2) a vertical, hinged wind structure or fin, and (3) a power takeoff system. The wing structure responds to the wind with an oscillating motion, generating power. The overall project goal was to determine the basic technical feasibility of the wind fin technology. Specific objectives were the following: (1) to determine the wind energy-conversion performance of the wind fin and the degree to which its performance could be enhanced through basic design improvements; (2) to determine how best to design the wind fin system to survive extreme winds; (3) to determine the cost-effectiveness of the best wind fin designs compared to state-of-the-art wind turbines; and (4) to develop conclusions about the overall technical feasibility of the wind fin system. Project work involved extensive computer modeling, wind-tunnel testing with small models, and testing of bench-scale models in a wind tunnel and outdoors in the wind. This project determined that the wind fin approach is technically feasible and likely to be commercially viable. Project results suggest that this new technology has the potential to harvest wind energy at approximately half the system cost of wind turbines in the 10kW range. Overall, the project demonstrated that the wind fin technology has the potential to increase the economic viability of small wind-power generation. In addition, it has the potential to eliminate lethality to birds and bats, overcome public objections to the aesthetics of wind-power machines, and significantly expand wind-power’s contribution to the national energy supply.

  15. A model for the non-universal power-law of the solar wind sub-ion scale magnetic spectrum

    E-Print Network [OSTI]

    Passot, T

    2015-01-01

    A phenomenological turbulence model for kinetic Alfv\\'en waves in a magnetized collisionless plasma, able to reproduce the non-universal power-law spectra observed at the sub-ion scales in the solar wind and the terrestrial magnetosphere, is presented. Nonlocal interactions are retained, and critical balance, characteristic of a strong turbulence regime, establishes dynamically as the cascade proceeds. The process of temperature homogenization along distorted magnetic field lines, induced by Landau damping, affects the turbulence transfer time and results in a steepening of the sub-ion power-law spectrum of critically-balanced turbulence, whose exponent is in particular sensitive to the ratio between the Alfv\\'en wave period and the nonlinear timescale.

  16. Coupling a Mesoscale Numerical Weather Prediction Model with Large-Eddy Simulation for Realistic Wind Plant Aerodynamics Simulations (Poster)

    SciTech Connect (OSTI)

    Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.

    2014-06-01

    Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.

  17. Gone with the Wind - The Potential Tragedy of the Common Wind

    E-Print Network [OSTI]

    Lifshitz-Goldberg, Yaei

    2010-01-01

    As a result wind turbines can produce energy in winds as lowelectric energy to generate wind, a wind turbine utilizesWind Turbine Projects to Encourage Utilization of Wind Energy

  18. A comparison of turbulence models in airship steady-state CFD simulations

    E-Print Network [OSTI]

    Voloshin, Vitaly; Calay, Rajnish K

    2012-01-01

    The accuracy and resource consumption of the four different turbulence models based on the eddy viscosity assumption, namely, $k-\\varepsilon$, two $k-\\omega$ and Spallart-Allmaram models, in modeling airships are investigated. The test airship shape is a conventional shape. Three different angles of attack are considered. The results are checked against the wind tunnel experimental data. The resource consumption study is based on the benchmark of 1500 iterations. Based on all data obtained it is evident that Spallart-Allmaras model is the most optimal one in the majority of cases.

  19. Quantifying Offshore Wind Resources from Satellite Wind Maps

    E-Print Network [OSTI]

    Pryor, Sara C.

    the spatial extent of the wake behind large offshore wind farms. Copyright © 2006 John Wiley & Sons, LtdQuantifying Offshore Wind Resources from Satellite Wind Maps: Study Area the North Sea C. B National Laboratory, Roskilde, Denmark Offshore wind resources are quantified from satellite synthetic

  20. Reference wind farm selection for regional wind power prediction models

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Reference wind farm selection for regional wind power prediction models Nils Siebert George.siebert@ensmp.fr, georges.kariniotakis@ensmp.fr Abstract Short-term wind power forecasting is recognized today as a major requirement for a secure and economic integration of wind generation in power systems. This paper deals