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1

Supercomputers Capture Turbulence in the Solar Wind  

NLE Websites -- All DOE Office Websites (Extended Search)

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

2

Wind turbulence characterization for wind energy development  

DOE Green Energy (OSTI)

As part of its support of the US Department of Energy's (DOE's) Federal Wind Energy Program, the Pacific Northwest Laboratory (PNL) has initiated an effort to work jointly with the wind energy community to characterize wind turbulence in a variety of complex terrains at existing or potential sites of wind turbine installation. Five turbulence characterization systems were assembled and installed at four sites in the Tehachapi Pass in California, and one in the Green Mountains near Manchester, Vermont. Data processing and analyses techniques were developed to allow observational analyses of the turbulent structure; this analysis complements the more traditional statistical and spectral analyses. Preliminary results of the observational analyses, in the rotating framework or a wind turbine blade, show that the turbulence at a site can have two major components: (1) engulfing eddies larger than the rotor, and (2) fluctuating shear due to eddies smaller than the rotor disk. Comparison of the time series depicting these quantities at two sites showed that the turbulence intensity (the commonly used descriptor of turbulence) did not adequately characterize the turbulence at these sites. 9 refs., 10 figs.,

Wendell, L.L.; Gower, G.L.; Morris, V.R.; Tomich, S.D.

1991-09-01T23:59:59.000Z

3

Supercomputers Capture Turbulence in the Solar Wind  

NLE Websites -- All DOE Office Websites (Extended Search)

Provide Web Site Feedback: info@es.net Supercomputers Capture Turbulence in the Solar Wind Berkeley Lab visualizations could help scientists forecast destructive space...

4

k-? turbulence modeling for a wind turbine.  

E-Print Network (OSTI)

?? In this report we discuss the use of k-? RANS (Reynolds-averaged Navier-Stokes equations) turbulence model for wind turbine applications. This model has been implemented… (more)

EREK, ERMAN

2011-01-01T23:59:59.000Z

5

Supercomputers Capture Turbulence in the Solar Wind  

NLE Websites -- All DOE Office Websites (Extended Search)

Supercomputers Supercomputers Capture Turbulence in the Solar Wind Supercomputers Capture Turbulence in the Solar Wind Berkeley Lab visualizations could help scientists forecast destructive space weather December 16, 2013 Linda Vu, +1 510 495 2402, lvu@lbl.gov eddies1.jpg This visualization zooms in on current sheets revealing the "cascade of turbulence" in the solar wind occurring down to electron scales. This is a phenomenon common in fluid dynamics-turbulent energy injected at large eddies is transported to successively smaller scales until it is dissipated as heat. (Image by Burlen Loring, Berkeley Lab) As inhabitants of Earth, our lives are dominated by weather. Not just in the form of rain and snow from atmospheric clouds, but also a sea of charged particles and magnetic fields generated by a star sitting 93

6

Turbulent Spectra in the Solar Wind Plasma  

E-Print Network (OSTI)

Observations of interstellar scintillations at radio wavelengths reveal a Kolmogorov-like scaling of the electron density spectrum with a spectral slope of -5/3 over six decades in wavenumber space. A similar turbulent density spectrum in the solar wind plasma has been reported. The energy transfer process in the magnetized solar wind plasma over such extended length-scales remains an unresolved paradox of modern turbulence theories raising the especially intriguing question of how a compressible magnetized solar wind exhibits a turbulent spectrum that is a characteristic of an incompressible hydrodynamic fluid. To address these questions, we have undertaken three-dimensional time dependent numerical simulations of a compressible magnetohydrodynamic fluid describing super-Alfv\\'enic, supersonic and strongly magnetized plasma. It is shown that the observed Kolmogorov-like (-5/3) spectrum can develop in the solar wind plasma by supersonic plasma motions that dissipate into highly subsonic motion that passively ...

Shaikh, Dastgeer

2009-01-01T23:59:59.000Z

7

Supercomputers Capture Turbulence in the Solar Wind  

NLE Websites -- All DOE Office Websites (Extended Search)

Supercomputers Capture Supercomputers Capture Turbulence in the Solar Wind News & Publications ESnet in the News ESnet News Media & Press Publications and Presentations Galleries ESnet Awards and Honors Contact Us Technical Assistance: 1 800-33-ESnet (Inside the US) 1 800-333-7638 (Inside the US) 1 510-486-7600 (Globally) 1 510-486-7607 (Globally) Report Network Problems: trouble@es.net Provide Web Site Feedback: info@es.net Supercomputers Capture Turbulence in the Solar Wind Berkeley Lab visualizations could help scientists forecast destructive space weather December 16, 2013 | Tags: ESnet News, National Energy Research Scientific Computing Linda Vu, +1 510 495 2402, lvu@lbl.gov eddies1.jpg This visualization zooms in on current sheets revealing the "cascade of turbulence" in the solar wind occurring down to electron scales. This is

8

Anisotropic MHD Turbulence in the Interstellar Medium and Solar Wind  

E-Print Network (OSTI)

Anisotropic MHD Turbulence in the Interstellar Medium and Solar Wind C. S. Ng Center for Magnetic (MHD) turbulence Observations in ISM and solar wind · Anisotropy due to magnetic field · Electron MHD turbulence #12;Interstellar turbulence From Cordes (1999) Observation: power law relation between electron

Ng, Chung-Sang

9

Turbulent Density Spectrum in Solar Wind Plasma  

E-Print Network (OSTI)

The density fluctuation spectrum in the solar wind reveals a Kolmogorov-like scaling with a spectral slope of -5/3 in wavenumber space. The energy transfer process in the magnetized solar wind, characterized typically by MHD turbulence, over extended length-scales remains an unresolved paradox of modern turbulence theories, raising the question of how a compressible magnetofluid exhibits a turbulent spectrum that is characteristic of an incompressible hydrodynamic fluid. To address these questions, we have undertaken three-dimensional time dependent numerical simulations of a compressible magnetohydrodynamic fluid describing super-Alfv\\'enic, supersonic and strongly magnetized plasma fluid. It is shown that a Kolmogorov-like density spectrum can develop by plasma motions that are dominated by Alfv\\'enic cascades whereas compressive modes are dissipated.

Shaikh, Dastgeer

2009-01-01T23:59:59.000Z

10

Can Wind Lidars Measure Turbulence?  

Science Conference Proceedings (OSTI)

Modeling of the systematic errors in the second-order moments of wind speeds measured by continuous-wave (ZephIR) and pulsed (WindCube) lidars is presented. These lidars use the conical scanning technique to measure the velocity field. The model ...

A. Sathe; J. Mann; J. Gottschall; M. S. Courtney

2011-07-01T23:59:59.000Z

11

Wind Access and Permitting Law | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Access and Permitting Law Wind Access and Permitting Law < Back Eligibility Residential Savings Category Wind Buying & Making Electricity Program Info State Delaware Program Type...

12

Effects of Wind Turbulence on Coherent Doppler Lidar Performance  

Science Conference Proceedings (OSTI)

The effects of wind turbulence on pulsed coherent Doppler lidar performance are investigated theoretically and with computer simulations. The performance of velocity estimators is determined for the case of a single realization of a wind field ...

Rod Frehlich

1997-02-01T23:59:59.000Z

13

Numerical simulations to study solar wind turbulence  

Science Conference Proceedings (OSTI)

Numerical simulation of coupled equations of kinetic Alfven wave (KAW) and ion acoustic wave is presented in the solar wind. The nonlinear dynamical equations satisfy the modified Zakharov system of equations by taking the nonadiabatic response of the background density. The ponderomotive nonlinearity is incorporated in the wave dynamics. The effect of Landau damping of KAW is taken into account. Localization of magnetic field intensity and the wavenumber spectra (perpendicular and parallel) of magnetic fluctuations are studied in solar plasmas around 1 a.u. Our results reveal the formation of damped localized structures and the steeper spectra that are in good agreement with the observations. These damped structures and steeper turbulent spectra can be responsible for plasma heating and particle acceleration in solar wind.

Sharma, R. P.; Sharma, Nidhi; Kumar, Sanjay [Centre for Energy Studies, Indian Institute of Technology Delhi, Delhi 110016 (India); Kumar, Sachin [Department of Applied Sciences and Humanities, Ajay Kumar Garg Engineering College, Ghaziabad 201009 (India); Singh, H. D. [Department of Physical Sciences, School of Physical and Chemical Sciences, Sikkim University, Sikkim 737102 (India)

2011-02-15T23:59:59.000Z

14

Identification of Wind Turbine Response to Turbulent Inflow Structures: Preprint  

DOE Green Energy (OSTI)

The National Renewable Energy Laboratory conducted an experiment to obtain detailed wind measurements and corresponding wind turbine measurements in order to establish a causal relationship between coherent turbulent structures and wind turbine blade fatigue loads. Data were collected for one entire wind season from October 2000 to May 2001. During this period, the wind turbine operated under atmospheric conditions that support the formation of coherent turbulent structures 31% of the time. Using the equivalent fatigue load parameter as a measure of wind turbine blade fatigue and using statistical measures of the turbulent fluctuations of the wind, general correlation between the turbulence and the wind turbine response is shown. Direct correlation cannot be resolved with 10-minute statistics for several reasons. Multiple turbulent structures can exist within a 10-minute record, and the equivalent fatigue load parameter is essentially a 10-minute statistic that cannot estimate turbine response to individual turbulent structures. Large-magnitude turbulent fluctuations in the form of instantaneous Reynolds stresses do not necessarily correspond directly to large-magnitude blade root moment amplitudes. Thus, additional work must be done to quantify the negative turbine response and to correlate this response to turbulent inflow parameters over time scales less than 10 minutes.

Hand, M. M.; Kelley, N. D.; Balas, M. J.

2003-06-01T23:59:59.000Z

15

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 RIS� DTU has started to build a newly designed laser-based lidar scanning facility for remote wind

16

COLLISIONLESS DAMPING AT ELECTRON SCALES IN SOLAR WIND TURBULENCE  

SciTech Connect

The dissipation of turbulence in the weakly collisional solar wind plasma is governed by unknown kinetic mechanisms. Two candidates have been suggested to play an important role in the dissipation, collisionless damping via wave-particle interactions and dissipation in small-scale current sheets. High resolution spacecraft measurements of the turbulent magnetic energy spectrum provide important constraints on the dissipation mechanism. The limitations of popular fluid and hybrid numerical schemes for simulation of the dissipation of solar wind turbulence are discussed, and instead a three-dimensional kinetic approach is recommended. We present a three-dimensional nonlinear gyrokinetic simulation of solar wind turbulence at electron scales that quantitatively reproduces the exponential form of the turbulent magnetic energy spectrum measured in the solar wind. A weakened cascade model that accounts for nonlocal interactions and collisionless Landau damping also quantitatively agrees with the observed exponential form. These results establish that a turbulent cascade of kinetic Alfven waves that is terminated by collisionless Landau damping is sufficient to explain the observed magnetic energy spectrum in the dissipation range of solar wind turbulence.

TenBarge, J. M.; Howes, G. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Dorland, W., E-mail: jason-tenbarge@uiowa.edu [Department of Physics, University of Maryland, College Park, MA 20742-3511 (United States)

2013-09-10T23:59:59.000Z

17

Effects of wind shear and turbulence on wind turbine power curves  

DOE Green Energy (OSTI)

It is a common practice to use wind speeds at hub height in determining wind turbine power curves. Although the possible influence of other variables (sub as turbulence and wind shear) is generally neglected in power curve measurements, we discovered the importance of other variables in an analysis of power curves for three 2.5 MW wind turbines. When the power curves were stratified by turbulence intensity. Such a large sensitivity to turbulence was not expected, and further analyses were conducted to determine if other factors accompanying the change in turbulence level could cause or contribute to the observed sensitivity of the power curves to turbulence. In summary, the sensitivity of the observed power curves was largely due to two factors: (1) an actual sensitivity to turbulence in determining the power curve and (2) the deviation of the disk-averaged velocity from the hub-height velocity under low turbulence conditions that were most prevalent at the site. An examination of the wind shear profiles over the height of the rotor disk revealed that low turbulence conditions were characterized by strong shear in the lower half of the rotor disk and weak or negative shear in the upper half. Implications of this analysis are that significant errors in power curve measurements can result if the effects of wind shear and turbulence are ignored. 7 refs., 6 figs.

Elliott, D.L. (Pacific Northwest Lab., Richland, WA (USA)); Cadogan, J.B. (USDOE, Washington, DC (USA))

1990-09-01T23:59:59.000Z

18

Generalized similarity in finite range solar wind magnetohydrodynamic turbulence  

E-Print Network (OSTI)

Extended or generalized similarity is a ubiquitous but not well understood feature of turbulence that is realized over a finite range of scales. ULYSSES spacecraft solar polar passes at solar minimum provide \\textit{in situ} observations of evolving anisotropic magnetohydrodynamic turbulence in the solar wind under ideal conditions of fast quiet flow. We find a single generalized scaling function characterises this finite range turbulence and is insensitive to plasma conditions. The recent unusually inactive solar minimum -with turbulent fluctuations down by a factor of $\\sim 2$ in power- provides a test of this invariance.

Chapman, S C

2009-01-01T23:59:59.000Z

19

Generation of residual energy in the turbulent solar wind  

SciTech Connect

In situ observations of the fluctuating solar wind flow show that the energy of magnetic field fluctuations always exceeds that of the kinetic energy, and therefore the difference between the kinetic and magnetic energies, known as the residual energy, is always negative. The same behaviour is found in numerical simulations of magnetohydrodynamic turbulence. We study the dynamics of the residual energy for strong, anisotropic, critically balanced magnetohydrodynamic turbulence using the eddy damped quasi-normal Markovian approximation. Our analysis shows that for stationary critically balanced magnetohydrodynamic turbulence, negative residual energy will always be generated by nonlinear interacting Alfven waves. This offers a general explanation for the observation of negative residual energy in solar wind turbulence and in the numerical simulations.

Gogoberidze, G. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom); Institute of Theoretical Physics, Ilia State University, 3/5 Cholokashvili Ave., 0162 Tbilisi (Georgia); Chapman, S. C.; Hnat, B. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom)

2012-10-15T23:59:59.000Z

20

Measurement of turbulent wind velocities using a rotating boom apparatus  

DOE Green Energy (OSTI)

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.

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

1984-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

A Tree Swaying in a Turbulent Wind: A Scaling Analysis  

E-Print Network (OSTI)

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 is in agreement 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.

Theo Odijk

2013-05-29T23:59:59.000Z

22

Estimation of turbulence level and scale for wind turbine applications  

DOE Green Energy (OSTI)

A simplified method is presented for estimating onsite turbulence variance within the wind turbine layer for horizontal wind speed. The method is based principally on estimating the probability distribution of wind speed and assigning a variance to each mean wind speed based on surface roughness estimates. The model is not proposed as an alternative to onsite measurement and analysis, but rather as an adjunct to such a program. A revision of the Kaimal neutral u-component spectrum is suggested to apply to the mix of the stabilities occurring during operational winds. Values of integral length scale calculated from data analysis are shown to contradict the length scale model implicit in turbulence power spectra. Also, these calculated values are shown to be extremely sensitive to the length of the time series and the detrending method used. The analysis and modeling are extended to the rotational frame of reference for a horizontal-axis wind turbine by modeling the ratios of harmonic spike variances (1P, 2P, etc.) in the rotational spectrum to the Eulerian turbulence variance. 15 refs., 11 figs., 3 tabs.

Powell, D.C.

1988-11-01T23:59:59.000Z

23

Using a new characterization of turbulent wind for accurate correlation of wind turbine response with wind speed  

SciTech Connect

The turbulence encountered by a point on a rotating wind turbine blade has characteristics that in some important respects are different from those measured by a stationary anemometer. The conventional one-peaked continuous spectrum becomes, broadly, a two-peaked spectrum that in addition contains a set of narrow-band spikes of turbulence energy, one centered on the frequency of rotor rotation and the others centered on multiples of that frequency. The rotational sampling effect on wind spectra is quantified using measurements of wind velocity by anemometers on stationary crosswind circular arrays. Characteristics of fluctuating wind are compared to measured fluctuations of bending moments of the rotor blades and power output fluctuations of a horizontal-axis wind turbine at the same site. The wind characteristics and the correlations between wind fluctuations and wind turbine fluctuations provide a basis for improving turbine design, siting, and control. 6 refs., 11 figs., 1 tab.

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

1987-09-01T23:59:59.000Z

24

Turbulent heating of the corona and solar wind: the heliospheric  

E-Print Network (OSTI)

of telegraph services - Once per 500 years (ice cores) - Solar-terrestrial connection - Interplanetary space of radiators - Dust environment - Cp/Cg problems - Solar panels and power #12;Solar Probe Plus 2018 launch 35Turbulent heating of the corona and solar wind: the heliospheric dark energy problem Stuart D. Bale

25

Residual energy in magnetohydrodynamic turbulence and in the solar wind  

E-Print Network (OSTI)

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.

Stanislav Boldyrev; Jean Carlos Perez; Vladimir Zhdankin

2011-08-30T23:59:59.000Z

26

Solar/Wind Access Policy | Open Energy Information  

Open Energy Info (EERE)

Solar/Wind Access Policy Solar/Wind Access Policy < Solar Jump to: navigation, search Solar and wind access laws are designed to establish a right to install and operate a solar or wind energy system at a home or other facility. Some solar access laws also ensure a system owner's access to sunlight. These laws may be implemented at both the state and local levels. In some states, access rights prohibit homeowners associations, neighborhood covenants and local ordinances from restricting a homeowner's right to use solar energy. Easements, the most common form of solar access law, allow for the rights to existing access to a renewable resource on the part of one property owner to be secured from an owner whose property could be developed in such a way as to restrict that resource. An easement is

27

Modelling the Vertical Wind Speed and Turbulence Intensity Profiles at Prospective Offshore Wind Farm Sites  

E-Print Network (OSTI)

Monin-Obukhov theory predicts the well-known log-linear form of the vertical wind speed profile. A turbulence intensity profile can be estimated from this by assuming that the standard deviation of the wind speed is proportional to the friction velocity. Two parameters, namely the aerodynamic surface roughness length and the MoninObukhov length, are than needed to predict the vertical wind speed and turbulence intensity profiles from a measurement at one height. Different models to estimate these parameters for conditions important for offshore wind energy utilisation are compared and tested: Four models for the surface roughness and three methods to derive the Monin-Obukov-length from measurements. They have been tested with data from the offshore field measurement Rdsand by extrapolating the measured 10 m wind speed to 50 m height and comparing it with the measured 50 m wind speed.

Bernhard Lange; Søren Larsen; Jørgen Højstrup; Rebecca Barthelmie; Ulrich Focken

2002-01-01T23:59:59.000Z

28

Measurements of Wind and Turbulence Profiles with Scanning Doppler Lidar for Wind Energy Applications  

SciTech Connect

High-quality profiles of mean and turbulent statistics of the wind field upstream of a wind farm can be produced using a scanning Doppler lidar. Careful corrections for the spatial filtering of the wind field by the lidar pulse produce turbulence estimates equivalent to point sensors but with the added advantage of a larger sampling volume to increase the statistical accuracy of the estimates. For a well-designed lidar system, this permits accurate estimates of the key turbulent statistics over various subdomains and with sufficiently short observation times to monitor rapid changes in conditions. These features may be ideally suited for optimal operation of wind farms and also for improved resource assessment of potential sites.

Frehlich, R.; Kelley, N.

2008-03-01T23:59:59.000Z

29

Remote Measurement of Turbulent Wind Spectra by Heterodyne DopplerLidar Technique  

Science Conference Proceedings (OSTI)

Heterodyne Doppler lidars (HDLs) are used to monitor atmospheric wind field and wind turbulence at remote distance. This last application calls for the derivation of wind spectra, which can be characterized by the dissipation rate and the ?-...

Philippe Drobinski; Alain M. Dabas; Pierre H. Flamant

2000-12-01T23:59:59.000Z

30

Parallel Electric Field Spectrum of Solar Wind Turbulence  

E-Print Network (OSTI)

By searching through more than 10 satellite-years of THEMIS and Cluster data, three reliable examples of parallel electric field turbulence in the undisturbed solar wind have been found. The perpendicular and parallel electric field spectra in these examples have similar shapes and amplitudes, even at large scales (frequencies below the ion gyroscale) where Alfvenic turbulence with no parallel electric field component is thought to dominate. The spectra of the parallel electric field fluctuations are power laws with exponents near -5/3 below the ion scales (~ 0.1 Hz), and with a flattening of the spectrum in the vicinity of this frequency. At small scales (above a few Hz), the spectra are steeper than -5/3 with values in the range of -2.1 to -2.8. These steeper slopes are consistent with expectations for kinetic Alfven turbulence, although their amplitude relative to the perpendicular fluctuations is larger than expected.

Mozer, F S

2013-01-01T23:59:59.000Z

31

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

New Hampshire, University of

32

Wind Shear and Turbulence Profiles at Elevated Heights: Great Lakes and Midwest Sites (Poster)  

DOE Green Energy (OSTI)

Analyzed wind resource characteristics at elevated heights (50 m-200+m) incuding shear and turbulence profiles for some areas of the Great Lakes and M idwest sites.

Elliott, D.; Schwartz, M.; Scott, G.

2009-05-01T23:59:59.000Z

33

Velocity-Space Proton Diffusion in the Solar Wind Turbulence  

E-Print Network (OSTI)

We study a velocity-space quasilinear diffusion of the solar wind protons driven by oblique Alfven turbulence at proton kinetic scales. Turbulent fluctuations at these scales possess properties of kinetic Alfven waves (KAWs) that are efficient in Cherenkov resonant interactions. The proton diffusion proceeds via Cherenkov kicks and forms a quasilinear plateau - nonthermal proton tail in the velocity distribution function (VDF). The tails extend in velocity space along the mean magnetic field from 1 to (1.5-3) VA, depending on the spectral break position, turbulence amplitude at the spectral break, and spectral slope after the break. The most favorable conditions for the tail generation occur in the regions where the proton thermal and Alfven velocities are about the same, VTp/VA = 1. The estimated formation times are within 1-2 h for typical tails at 1 AU, which is much shorter than the solar wind expansion time. Our results suggest that the nonthermal proton tails, observed in-situ at all heliocentric distan...

Voitenko, Yuriy

2013-01-01T23:59:59.000Z

34

Comparison of Mean Wind Speeds and Turbulence at a Coastal Site and Offshore Location  

Science Conference Proceedings (OSTI)

Observations of mean wind speed and longitudinal turbulence at a height of 8 m over the Atlantic ocean, 5 km off Long Island, New York, were compared with simultaneous observations at the beach. Results were grouped into wind direction classes ...

S. SethuRaman; G. S. Raynor

1980-01-01T23:59:59.000Z

35

Study of Radiative and Turbulent Processes in the Stable Boundary Layer under Weak Wind Conditions  

Science Conference Proceedings (OSTI)

The role of radiation and turbulence was studied in a weak wind nocturnal inversion layer using a one-dimensional model. In contrast to a strong wind stable boundary layer where cooling within the surface inversion layer is dominated by ...

S. G. Gopalakrishnan; Maithili Sharan; R. T. McNider; M. P. Singh

1998-03-01T23:59:59.000Z

36

User's guide for a personal computer model of turbulence at a wind turbine rotor  

DOE Green Energy (OSTI)

This document is primarily (1) a user's guide for the personal computer (PC) version of the code for the PNL computational model of the rotationally sampled wind speed (RODASIM11) and (2) a brief guide to the growing literature on the subject of rotationally sampled turbulence, from which the model is derived. The model generates values of turbulence experienced by single points fixed in the rotating frame of reference of an arbitrary wind turbine blade. The character of the turbulence depends on the specification of mean wind speed, the variance of turbulence, the crosswind and along-wind integral scales of turbulence, mean wind shear, and the hub height, radius, and angular speed of rotation of any point at which wind fluctuation is to be calculated. 13 refs., 4 figs., 4 tabs.

Connell, J.R.; Powell, D.C.; Gower, G.L.

1989-08-01T23:59:59.000Z

37

Modeling access to wind resources in the United States  

DOE Green Energy (OSTI)

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.

Short, W.D.

1999-10-20T23:59:59.000Z

38

THREE-DIMENSIONAL STRUCTURE OF SOLAR WIND TURBULENCE  

SciTech Connect

We present a measurement of the scale-dependent, three-dimensional structure of the magnetic field fluctuations in inertial range solar wind turbulence with respect to a local, physically motivated coordinate system. The Alfvenic fluctuations are three-dimensionally anisotropic, with the sense of this anisotropy varying from large to small scales. At the outer scale, the magnetic field correlations are longest in the local fluctuation direction, consistent with Alfven waves. At the proton gyroscale, they are longest along the local mean field direction and shortest in the direction perpendicular to the local mean field and the local field fluctuation. The compressive fluctuations are highly elongated along the local mean field direction, although axially symmetric perpendicular to it. Their large anisotropy may explain why they are not heavily damped in the solar wind.

Chen, C. H. K.; Bale, S. D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Mallet, A.; Schekochihin, A. A. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom); Horbury, T. S. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Wicks, R. T., E-mail: chen@ssl.berkeley.edu [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-10-20T23:59:59.000Z

39

Inflow Turbulence Energy and its Spatial Distribution on a Wind Turbine  

E-Print Network (OSTI)

Inflow Turbulence Energy and its Spatial Distribution on a Wind Turbine Christopher Wright Dr caused the most variability of turbulence energy while high wind shear exponents caused the least........................................................................................................................ 18 #12;Completion report on our project to empirically evaluate energy distribution in unique spatial

Manuel, Lance

40

THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC MODELING OF THE SOLAR WIND INCLUDING PICKUP PROTONS AND TURBULENCE TRANSPORT  

Science Conference Proceedings (OSTI)

To study the effects of interstellar pickup protons and turbulence on the structure and dynamics of the solar wind, we have developed a fully three-dimensional magnetohydrodynamic solar wind model that treats interstellar pickup protons as a separate fluid and incorporates the transport of turbulence and turbulent heating. The governing system of equations combines the mean-field equations for the solar wind plasma, magnetic field, and pickup protons and the turbulence transport equations for the turbulent energy, normalized cross-helicity, and correlation length. The model equations account for photoionization of interstellar hydrogen atoms and their charge exchange with solar wind protons, energy transfer from pickup protons to solar wind protons, and plasma heating by turbulent dissipation. Separate mass and energy equations are used for the solar wind and pickup protons, though a single momentum equation is employed under the assumption that the pickup protons are comoving with the solar wind protons. We compute the global structure of the solar wind plasma, magnetic field, and turbulence in the region from 0.3 to 100 AU for a source magnetic dipole on the Sun tilted by 0 Degree-Sign -90 Degree-Sign and compare our results with Voyager 2 observations. The results computed with and without pickup protons are superposed to evaluate quantitatively the deceleration and heating effects of pickup protons, the overall compression of the magnetic field in the outer heliosphere caused by deceleration, and the weakening of corotating interaction regions by the thermal pressure of pickup protons.

Usmanov, Arcadi V.; Matthaeus, William H. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Goldstein, Melvyn L., E-mail: arcadi.usmanov@nasa.gov [Code 673, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Transient Evolution of Langmuir Turbulence in Ocean Boundary Layers Driven by Hurricane Winds and Waves  

Science Conference Proceedings (OSTI)

A large-eddy simulation (LES) model, which adopts wave-averaged equations with vortex force, is used to investigate Langmuir turbulence and ocean boundary layer (OBL) dynamics in high-wind hurricane conditions. The temporally evolving spatially ...

Peter P. Sullivan; Leonel Romero; James C. McWilliams; W. Kendall Melville

2012-11-01T23:59:59.000Z

42

Large-Eddy Simulation of Langmuir Turbulence in Pure Wind Seas  

Science Conference Proceedings (OSTI)

The scaling of turbulent kinetic energy (TKE) and its vertical component (VKE) in the upper ocean boundary layer, forced by realistic wind stress and surface waves including the effects of Langmuir circulations, is investigated using large-eddy ...

Ramsey R. Harcourt; Eric A. D’Asaro

2008-07-01T23:59:59.000Z

43

Spaced-Antenna Interferometry to Measure Crossbeam Wind, Shear, and Turbulence: Theory and Formulation  

Science Conference Proceedings (OSTI)

The theory of measuring crossbeam wind, shear, and turbulence within the radar’s resolution volume V6 is described. Spaced-antenna weather radar interferometry is formulated for such measurements using phased-array weather radar. The formulation ...

Guifu Zhang; Richard J. Doviak

2007-05-01T23:59:59.000Z

44

A Volume-Imaging Radar Wind Profiler for Atmospheric Boundary Layer Turbulence Studies  

Science Conference Proceedings (OSTI)

This paper describes the turbulent eddy profiler (TEP), a volume-imaging, UHF radar wind profiler designed for clear-air measurements in the atmospheric boundary layer on scales comparable to grid cell sizes of large eddy simulation models. TEP ...

James B. Mead; Geoffrey Hopcraft; Stephen J. Frasier; Brian D. Pollard; Christopher D. Cherry; Daniel H. Schaubert; Robert E. McIntosh

1998-08-01T23:59:59.000Z

45

The Relationships among Wind, Horizontal Pressure Gradient, and Turbulent Momentum Transport during CASES-99  

Science Conference Proceedings (OSTI)

Relationships among the horizontal pressure gradient, the Coriolis force, and the vertical momentum transport by turbulent fluxes are investigated using data collected from the Cooperative Atmosphere-Surface Exchange Study in 1999 (CASES99). Wind ...

Jielun Sun; Donald H. Lenschow; Larry Mahrt; Carmen Nappo

46

Prediction of the Proton-to-Total Turbulent Heating in the Solar Wind  

E-Print Network (OSTI)

This paper employs a recent turbulent heating prescription to predict the ratio of proton-to-total heating due to the kinetic dissipation of Alfvenic turbulence as a function of heliocentric distance. Comparing to a recent empirical estimate for this turbulent heating ratio in the high-speed solar wind, the prediction shows good agreement with the empirical estimate for R >~ 0.8 AU, but predicts less ion heating than the empirical estimate at smaller heliocentric radii. At these smaller radii, the turbulent heating prescription, calculated in the gyrokinetic limit, fails because the turbulent cascade is predicted to reach the proton cyclotron frequency before Landau damping terminates the cascade. These findings suggest that the turbulent cascade can reach the proton cyclotron frequency at R ~ 0.8 AU, this turbulent heating prescription contains all of the necessary physical mechanisms needed to reproduce the empirically estimated proton-to-total heating ratio.

Howes, G G

2011-01-01T23:59:59.000Z

47

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

E-Print Network (OSTI)

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

Miami, University of

48

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

SciTech Connect

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.

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)

2012-08-10T23:59:59.000Z

49

Analysis of Wind and Turbulence Fields in a Region with Complex Orography  

Science Conference Proceedings (OSTI)

In a region of about 1000 km2 with complex orography, 1-h averages of wind and turbulence fields were analyzed over a period of 1 yr. It was shown that spatial homogeneity and temporal stationarity of the wind fields as well as the degree of ...

Waldemar Feller; Fritz Gassmann

1997-09-01T23:59:59.000Z

50

Lidar Measurement of Turbulence Encountered by Horizontal-Axis Wind Turbines  

Science Conference Proceedings (OSTI)

We used a continuous-wave (CW) Doppler lidar to measure wind velocity turbulence from a moving frame of reference. By directing the lidar beam to trace the perimeters of vertical-plane disks about horizontal axes parallel to the mean wind ...

R. M. Hardesty; B. F. Weber

1987-03-01T23:59:59.000Z

51

Propagation of Wind Energy into the Deep Ocean through a Fully Turbulent Mesoscale Eddy Field  

Science Conference Proceedings (OSTI)

The authors analyze the 3D propagation of wind-forced near-inertial motions in a fully turbulent mesoscale eddy field with a primitive equation numerical model. Although the wind stress is uniform, the near-inertial motion field quickly becomes ...

Eric Danioux; Patrice Klein; Pascal Rivière

2008-10-01T23:59:59.000Z

52

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

DOE Green Energy (OSTI)

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.

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

2005-08-01T23:59:59.000Z

53

Remote Determination of Winds, Turbulence Spectra and Energy Dissipation Rates in the Boundary Layer from Lidar Measurements  

Science Conference Proceedings (OSTI)

Procedures are described for the analysis of lidar data to remotely measure 1) spectra of aerosol density fluctuations, 2) radial and transverse components of the mean wind and turbulent fluctuations of the transverse component of the wind ...

K. E. Kunkel; E. W. Eloranta; J. A. Weinman

1980-05-01T23:59:59.000Z

54

Scaling Laws of Turbulence and Heating of Fast SolarWind: The Role of Density Fluctuations  

E-Print Network (OSTI)

Incompressible and isotropic magnetohydrodynamic turbulence in plasms can be described by an exact relation for the energy flux through the scales. This Yaglom-like scaling law has been recently observed in the solar wind above the solar poles observed by the Ulysses spacecraft, where the turbulence is in an Alfv\\'enic state. An analogous phenomenological scaling law, suitably modified to take into account compressible fluctuations, is observed more frequently in the same dataset. Large scale density fluctuations, despite their low amplitude, play thus a crucial role in the basic scaling properties of turbulence. The turbulent cascade rate in the compressive case can moreover supply the energy dissipation needed to account for the local heating of the non-adiabatic solar wind.

Carbone, V; Sorriso-Valvo, L; Noullez, A; Bruno, R

2010-01-01T23:59:59.000Z

55

Processing of turbulence-layer wind speed with Generalized SCIDAR through wavelet analysis  

E-Print Network (OSTI)

We describe a new method involving wavelet transforms for deriving the wind velocity associated with atmospheric turbulence layers from Generalized SCIDAR measurements. The algorithm analyses the cross-correlation of a series of scintillation patterns separated by lapses of Dt, 2Dt, 3Dt, 4Dt and 5Dt using wavelet transforms. Wavelet analysis provides the position, direction and altitude of the different turbulence layers detected in each cross-correlation. The comparison and consistency of the turbulent layer displacements in consecutive cross-correlations allow the determination of their velocities and avoid misidentifications associated with noise and/or overlapping layers. To validate the algorithm, we have compared the velocity of turbulence layers derived on four nights with the wind vertical profile provided by balloon measurements. The software is fully automated and is able to analyse huge amounts of Generalized SCIDAR measurements.

B. Garcia-Lorenzo; J. J. Fuensalida

2006-08-28T23:59:59.000Z

56

Modification of Proton Velocity Distributions by Alfvenic Turbulence in the Solar Wind  

E-Print Network (OSTI)

In the present paper, the proton velocity distribution function (VDF)in the solar wind is determined by solving numerically the kinetic evolution equation. We compare the results obtained when considering the effects of ex- ternal forces and Coulomb collisions with those obtained by adding effects of Alfven wave turbulence. We use Fokker-Planck diffusion terms due to Alfvenic turbulence, which take into account observed turbulence spectra and kinetic effects of finite proton gyroradius. Assuming a displaced Maxwellian for the proton VDF at the simulation boundary at 14 solar radii, we show that the turbulence leads to a fast (within several solar radii) development of the anti-sunward tail in the proton VDF. Our results provide a natural explanation for the nonthermal tails in the proton VDFs, which are often observed in-situ in the solar wind beyond 0.3 AU.

Pierrard, Viviane

2013-01-01T23:59:59.000Z

57

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

Science Conference Proceedings (OSTI)

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.

Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J. [Physics Department and Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire (United States); Stawarz, Joshua E. [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, Boulder, Colorado (United States); Forman, Miriam A. [Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York (United States)

2013-06-13T23:59:59.000Z

58

Lidar measurement of wind velocity turbulence spectra encountered by a rotating turbine blade  

DOE Green Energy (OSTI)

A homodyne CO/sub 2/ lidar system beam was conically scanned around a horizontal axis to measure the wind speed and turbulence characteristics encountered by a rotating turbine blade. Turbulence spectra obtained from the scanning lidar differed considerably from those calculated from fixed-point anemometer measurements, showing a redistribution of energy from lower to higher frequencies. The differences appeared more pronounced during periods when the atmosphere was stable.

Hardesty, R.M.; Korrell, J.A.; Hall, F.F. Jr.

1982-01-01T23:59:59.000Z

59

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

Science Conference Proceedings (OSTI)

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.

Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J. [Physics Department and Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH (United States); Stawarz, Joshua E. [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, Boulder, CA (United States); Forman, Miriam A., E-mail: jtu46@wildcats.unh.edu, E-mail: Charles.Smith@unh.edu, E-mail: Bernie.Vasquez@unh.edu, E-mail: Joshua.Stawarz@Colorado.edu, E-mail: Miriam.Forman@sunysb.edu [Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, NY (United States)

2012-08-01T23:59:59.000Z

60

City of Madison - Solar and Wind Access and Planning Laws | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

City of Madison - Solar and Wind Access and Planning Laws City of Madison - Solar and Wind Access and Planning Laws City of Madison - Solar and Wind Access and Planning Laws < Back Eligibility Construction Savings Category Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Water Heating Wind Program Info State Wisconsin Program Type Solar/Wind Access Policy Provider City of Madison Madison, Wisconsin, has established several local laws to facilitate the planning and permitting of solar and wind systems. The planning guidelines are specific to solar, while the permitting laws and procedures include wind as well. '''Planning''' To facilitate solar access, Madison's land subdivision regulations require streets to be "oriented in an east-west direction to the maximum

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Electron and proton heating by solar wind turbulence  

E-Print Network (OSTI)

Previous formulations of heating and transport associated with strong magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate internal energy equations for electrons and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both electrons and protons, and is exchanged between them via collisions. Comparison to available Ulysses data shows that a reasonable accounting for the data is provided when (i) the energy exchange timescale is very long and (ii) the deposition of heat due to turbulence is divided, with 60% going to proton heating and 40% into electron heating. Heat conduction, determined here by an empirical fit, plays a major role in describing the electron data.

Breech, B; Cranmer, S R; Kasper, J C; Oughton, S

2009-01-01T23:59:59.000Z

62

Petascale Simulations of Inhomogeneous Alfven Turbulence in the Solar Wind  

NLE Websites -- All DOE Office Websites (Extended Search)

A snapshot of turbulent magnetic field lines (red) inside a coronal hole that expands from a small patch on the solar surface to 5 solar radii A snapshot of turbulent magnetic field lines (red) inside a coronal hole that expands from a small patch on the solar surface to 5 solar radii A snapshot of turbulent magnetic field lines (red) inside a coronal hole that expands from a small patch on the solar surface to 5 solar radii. Alfven waves (AW), launched by convective motions on the photosphere, propagate in the inhomogeneous Solar atmosphere producing primary reflected waves that interact non-linearly with the outward waves, driving a turbulent cascade. This cascade continues with secondary reflections in a very complex interplay between wave reflections and nonlinear interactions. Selected slices across the simulation domain show contours of plasma current, indicating the generation of small scale structures where the

63

PREDICTION OF THE PROTON-TO-TOTAL TURBULENT HEATING IN THE SOLAR WIND  

SciTech Connect

This paper employs a recent turbulent heating prescription to predict the ratio of proton-to-total heating due to the kinetic dissipation of Alfvenic turbulence as a function of heliocentric distance. Comparing to a recent empirical estimate for this turbulent heating ratio in the high-speed solar wind, the prediction shows good agreement with the empirical estimate for R {approx}> 0.8 AU, but predicts less ion heating than the empirical estimate at smaller heliocentric radii. At these smaller radii, the turbulent heating prescription, calculated in the gyrokinetic limit, fails because the turbulent cascade is predicted to reach the proton cyclotron frequency before Landau damping terminates the cascade. These findings suggest that the turbulent cascade can reach the proton cyclotron frequency at R {approx}< 0.8 AU, leading to a higher level of proton heating than predicted by the turbulent heating prescription in the gyrokinetic limit. At larger heliocentric radii, R {approx}> 0.8 AU, this turbulent heating prescription contains all of the necessary physical mechanisms needed to reproduce the empirically estimated proton-to-total heating ratio.

Howes, G. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)

2011-09-01T23:59:59.000Z

64

Effects of turbulence on power generation for variable-speed wind turbines  

DOE Green Energy (OSTI)

One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.

Muljadi, E.; Butterfield, C.P.; Buhl, M.L. Jr.

1996-11-01T23:59:59.000Z

65

Quasilinear Evolution of Kinetic Alfven Wave Turbulence and Perpendicular Ion Heating in the Solar Wind  

E-Print Network (OSTI)

It is shown that the quasi-linear evolution of ion and electron distribution functions as result of wave-particle interaction of Kinetic Alfven Waves in the turbulent solar wind plasma leads to instability of long wavelength electromagnetic cyclotron waves and to an increase of the ion temperature perpendicular to the magnetic field.

Rudakov, L; Ganguli, G; Mithaiwala, M

2010-01-01T23:59:59.000Z

66

Turbulence Anisotropy Determined by Wind Profiler Radar and Its Correlation with Rain Events in Montreal, Canada  

Science Conference Proceedings (OSTI)

Turbulence inhomogeneities at 3-m scales can be either isotropic or anisotropic, and the degree of anisotropy can be measured with VHF wind profiler radars. Studies over a period of two years in Montreal, Quebec, Canada, have shown that for this ...

Anna Hocking; Wayne K. Hocking

2007-01-01T23:59:59.000Z

67

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

DOE Green Energy (OSTI)

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.

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

2011-12-01T23:59:59.000Z

68

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

DOE Green Energy (OSTI)

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.

Fichtl, G.H.

1983-09-01T23:59:59.000Z

69

Oceanic Quasi-geostrophic Turbulence Forced by Stochastic Wind Fluctuations  

Science Conference Proceedings (OSTI)

The quasi-geostrophic response to stochastic wind fluctuations is calculated using a doubly periodic nonlinear model, with a vertical resolution of three modes in most cases. The influence of various parameters on the response is investigated: ...

Anne Marie Treguier; Bach Lien Hua

1987-03-01T23:59:59.000Z

70

Turbulent Heating in the Solar Wind and in the Solar Corona  

E-Print Network (OSTI)

In this paper we calculate the turbulent heating rates in the solar wind using the Kolmogorov-like MHD turbulence phenomenology with Kolmogorov's constants calculated by {\\it Verma and Bhattacharjee }[1995b,c]. We find that the turbulent heating can not account for the total heating of the nonAlfv\\'enic streams in the solar wind. We show that dissipation due to thermal conduction is also a potential heating source. Regarding the Alfv\\'enic streams, the predicted turbulent heating rates using the constants of {\\it Verma and Bhattacharjee }[1995c] are higher than the observed heating rates; the predicted dissipation rates are probably overestimates because Alfv\\'enic streams have not reached steady-state. We also compare the predicted turbulent heating rates in the solar corona with the observations; the Kolmogorov-like phenomenology predicts dissipation rates comparable to the observed heating rates in the corona [{\\it Hollweg, }% 1984], but Dobrowoly et al.'s generalized Kraichnan model yields heating rates much less than that required.

Mahendra K. Verma

1995-09-05T23:59:59.000Z

71

Turbulent Heating in the Solar Wind and in the Solar Corona  

E-Print Network (OSTI)

In this paper we calculate the turbulent heating rates in the solar wind using the Kolmogorov-like MHD turbulence phenomenology with Kolmogorov’s constants calculated by Verma and Bhattacharjee [1995b,c]. We find that the turbulent heating can not account for the total heating of the nonAlfvénic streams in the solar wind. We show that dissipation due to thermal conduction is also a potential heating source. Regarding the Alfvénic streams, the predicted turbulent heating rates using the constants of Verma and Bhattacharjee [1995c] are higher than the observed heating rates; the predicted dissipation rates are probably overestimates because Alfvénic streams have not reached steady-state. We also compare the predicted turbulent heating rates in the solar corona with the observations; the Kolmogorov-like phenomenology predicts dissipation rates comparable to the observed heating rates in the corona [Hollweg, 1984], but Dobrowoly et al.’s generalized Kraichnan model yields heating rates much less than that required. 1 1

Mahendra K. Verma

2008-01-01T23:59:59.000Z

72

Turbulence process domination under the combined forcings of wind stress, the Langmuir vortex force, and surface cooling  

Science Conference Proceedings (OSTI)

Turbulence in the ocean surface layer is generated by time-varying combinations of destabilizing surface buoyancy flux, wind stress forcing, and wave forcing through a vortex force associated with the surface wave field. Observations of time- and ...

A. E. Gargett; C. E. Grosch

73

Impact of Breaking Wave Form Drag on Near-Surface Turbulence and Drag Coefficient over Young Seas at High Winds  

Science Conference Proceedings (OSTI)

The effects of breaking waves on near-surface wind turbulence and drag coefficient are investigated using large-eddy simulation. The impact of intermittent and transient wave breaking events (over a range of scales) is modeled as localized form ...

Nobuhiro Suzuki; Tetsu Hara; Peter P. Sullivan

2013-02-01T23:59:59.000Z

74

A Free-Floating PIV System: Measurements of Small-Scale Turbulence under the Wind Wave Surface  

Science Conference Proceedings (OSTI)

An in situ free-floating underwater miniature particle image velocimetry (UWMPIV) system is developed and applied to measure the structure of turbulence in the aqueous side of the wind wave surface boundary layer. The UWMPIV system provides a ...

Binbin Wang; Qian Liao; Jianen Xiao; Harvey A. Bootsma

2013-07-01T23:59:59.000Z

75

Wind and Turbulence in a Sparse but Regular Plant Canopy  

Science Conference Proceedings (OSTI)

Wind velocity statistics from several points within a regular but sparse array of clumped corn plants are analyzed, with each clump consisting of 12 plants, having a mean height of 1.6 m and a collective leaf area of about 2.75 m2 and occupying ...

Andree Tuzet; John D. Wilson

2002-05-01T23:59:59.000Z

76

THE SLOW-MODE NATURE OF COMPRESSIBLE WAVE POWER IN SOLAR WIND TURBULENCE  

Science Conference Proceedings (OSTI)

We use a large, statistical set of measurements from the Wind spacecraft at 1 AU, and supporting synthetic spacecraft data based on kinetic plasma theory, to show that the compressible component of inertial range solar wind turbulence is primarily in the kinetic slow mode. The zero-lag cross-correlation C({delta}n, {delta}B{sub ||}) between proton density fluctuations {delta}n and the field-aligned (compressible) component of the magnetic field {delta}B{sub ||} is negative and close to -1. The typical dependence of C({delta}n, {delta}B{sub ||}) on the ion plasma beta {beta}{sub i} is consistent with a spectrum of compressible wave energy that is almost entirely in the kinetic slow mode. This has important implications for both the nature of the density fluctuation spectrum and for the cascade of kinetic turbulence to short wavelengths, favoring evolution to the kinetic Alfven wave mode rather than the (fast) whistler mode.

Howes, G. G.; Klein, K. G.; TenBarge, J. M. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Bale, S. D.; Chen, C. H. K.; Salem, C. S. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States)

2012-07-01T23:59:59.000Z

77

INVESTIGATION OF INTERMITTENCY IN MAGNETOHYDRODYNAMICS AND SOLAR WIND TURBULENCE: SCALE-DEPENDENT KURTOSIS  

SciTech Connect

The behavior of scale-dependent (or filtered) kurtosis is studied in the solar wind using magnetic field measurements from the ACE and Cluster spacecraft at 1 AU. It is also analyzed numerically with high-resolution magnetohydrodynamic spectral simulations. In each case the filtered kurtosis increases with wavenumber, implying the presence of coherent structures at the smallest scales. This phase coupling is related to intermittency in solar wind turbulence and the emergence of non-Gaussian statistics. However, it is inhibited by the presence of upstream waves and other phase-randomizing structures, which act to reduce the growth of kurtosis.

Wan Minping; Osman, Kareem T.; Matthaeus, William H. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Oughton, Sean, E-mail: mpwan@bartol.udel.edu [Department of Mathematics, University of Waikato, Hamilton 3240 (New Zealand)

2012-01-10T23:59:59.000Z

78

Wind reversals in turbulent Rayleigh-Benard convection  

E-Print Network (OSTI)

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 / (\

Francisco Fontenele Araujo; S. Grossmann; D. Lohse

2004-07-13T23:59:59.000Z

79

FRAME DEPENDENCE OF THE ELECTRIC FIELD SPECTRUM OF SOLAR WIND TURBULENCE  

Science Conference Proceedings (OSTI)

We present the first survey of electric field data using the ARTEMIS spacecraft in the solar wind to study inertial range turbulence. It was found that the average perpendicular spectral index of the electric field depends on the frame of measurement. In the spacecraft frame it is -5/3, which matches the magnetic field due to the large solar wind speed in Lorentz transformation. In the mean solar wind frame, the electric field is primarily due to the perpendicular velocity fluctuations and has a spectral index slightly shallower than -3/2, which is close to the scaling of the velocity. These results are an independent confirmation of the difference in scaling between the velocity and magnetic field, which is not currently well understood. The spectral index of the compressive fluctuations was also measured and found to be close to -5/3, suggesting that they are not only passive to the velocity but may also interact nonlinearly with the magnetic field.

Chen, C. H. K.; Bale, S. D.; Salem, C.; Mozer, F. S., E-mail: chen@ssl.berkeley.edu [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)

2011-08-20T23:59:59.000Z

80

Numerical Study of the Effects of Atmospheric and Wake Turbulence on Wind Turbine Dynamics  

SciTech Connect

Although the atmospheric sciences community has been studying the effects of atmospheric stability and surface roughness on the planetary boundary layer for some time, their effects on wind turbine dynamics have not been well studied. In this study, we performed numerical experiments to explore some of the effects of atmospheric stability and surface roughness on wind turbine dynamics. We used large-eddy simulation to create atmospheric winds and compute the wind turbine flows, and we modeled the wind turbines as revolving and flexible actuator lines coupled to a wind turbine structural and system dynamic model. We examined the structural moments about the wind turbine blade, low-speed shaft, and nacelle; power production; and wake evolution when large 5-MW turbines are subjected to winds generated from low- and high-surface roughness levels representative of offshore and onshore conditions, respectively, and also neutral and unstable atmospheric conditions. In addition, we placed a second turbine 7 rotor diameters downwind of the first one so that we could explore wake effects under these different conditions. The results show that the turbulent structures generated within the atmospheric boundary layer wind simulations cause isolated loading events at least as significant as when a turbine is waked by an upwind turbine. The root-mean-square (RMS) turbine loads are consistently larger when the surface roughness is higher. The RMS blade-root out-of-plane bending moment and low-speed shaft torque are higher when the atmospheric boundary layer is unstable as compared with when it is neutral. However, the RMS yaw moments are either equal or reduced in the unstable case as compared with the neutral case. For a given surface roughness, the ratio of power produced by the downwind turbine relative to that of the upwind turbine is 15-20% higher when the conditions are unstable as compared with neutral. For a given atmospheric stability, this power ratio is 10% higher with the onshore roughness value versus the offshore one. The main conclusion is that various coherent turbulent structures that form under different levels of atmospheric stability and surface roughness have important effects on wind turbine structural response, power production, and wake evolution.

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

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

City of Madison- Solar & Wind Access and Planning Laws  

Energy.gov (U.S. Department of Energy (DOE))

Madison, Wisconsin, has established several local laws to facilitate the planning and permitting of solar and wind systems. The planning guidelines are specific to solar, while the permitting laws...

82

Full vector (3-D) inflow simulation in natural and wind farm environments using an expanded version of the SNLWIND (Veers) turbulence code  

DOE Green Energy (OSTI)

We have recently expanded the numerical turbulence simulation (SNLWIND) developed by Veers [1] to include all three components of the turbulent wind vector. We have also configured the code to simulate the characteristics of turbulent wind fields upwind and downwind of a large wind farm, as well as over uniform, flat terrain. Veers`s original method only simulates the longitudinal component of the wind in neutral flow. This paper overviews the development of spectral distribution, spatial coherence, and cross correlation models used to expired the SNLWIND code to include the three components of the turbulent wind over a range of atmospheric stabilities. These models are based on extensive measurements of the turbulence characteristics immediately upwind and downwind of a large wind farm in San Gorgonio Pass, California.

Kelley, N.D.

1992-11-01T23:59:59.000Z

83

Full vector (3-D) inflow simulation in natural and wind farm environments using an expanded version of the SNLWIND (Veers) turbulence code  

DOE Green Energy (OSTI)

We have recently expanded the numerical turbulence simulation (SNLWIND) developed by Veers [1] to include all three components of the turbulent wind vector. We have also configured the code to simulate the characteristics of turbulent wind fields upwind and downwind of a large wind farm, as well as over uniform, flat terrain. Veers's original method only simulates the longitudinal component of the wind in neutral flow. This paper overviews the development of spectral distribution, spatial coherence, and cross correlation models used to expired the SNLWIND code to include the three components of the turbulent wind over a range of atmospheric stabilities. These models are based on extensive measurements of the turbulence characteristics immediately upwind and downwind of a large wind farm in San Gorgonio Pass, California.

Kelley, N.D.

1992-11-01T23:59:59.000Z

84

Cascade and Damping of Alfvén-Cyclotron Fluctuations: Application to Solar Wind Turbulence Spectrum  

E-Print Network (OSTI)

With the diffusion approximation, we study the cascade and damping of Alfv\\'{e}n-cyclotron fluctuations in solar plasmas numerically. Motivated by wave-wave couplings and nonlinear effects, we test several forms of the diffusion tensor. For a general locally anisotropic and inhomogeneous diffusion tensor in the wave vector space, the turbulence spectrum in the inertial range can be fitted with power-laws with the power-law index varying with the wave propagation direction. For several locally isotropic but inhomogeneous diffusion coefficients, the steady-state turbulence spectra are nearly isotropic in the absence of damping and can be fitted by a single power-law function. However, the energy flux is strongly polarized due to the inhomogeneity that leads to an anisotropic cascade. Including the anisotropic thermal damping, the turbulence spectrum cuts off at the wave numbers, where the damping rates become comparable to the cascade rates. The combined anisotropic effects of cascade and damping make this cutoff wave number dependent on the wave propagation direction, and the propagation direction integrated turbulence spectrum resembles a broken power-law, which cuts off at the maximum of the cutoff wave numbers or the $^4$He cyclotron frequency. Taking into account the Doppler effects, the model can naturally reproduce the broken power-law wave spectra observed in the solar wind and predicts that a higher break frequency is aways accompanied with a greater spectral index change that may be caused by the increase of the Alfv\\'{e}n Mach number, the reciprocal of the plasma beta, and/or the angle between the solar wind velocity and the mean magnetic field. These predictions can be tested by future observations.

Yan Wei Jiang; Siming Liu; Vahé Petrosian; Christopher L. Fryer

2008-02-07T23:59:59.000Z

85

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

E-Print Network (OSTI)

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.

A. Bershadskii

2009-08-27T23:59:59.000Z

86

TURBULENCE-DRIVEN POLAR WINDS FROM T TAURI STARS ENERGIZED BY MAGNETOSPHERIC ACCRETION  

E-Print Network (OSTI)

Pre-main-sequence stars are observed to be surrounded by both accretion flows and some kind of wind or jetlike outflow. Recent work by Matt and Pudritz has suggested that if classical T Tauri stars exhibit stellar winds with massloss rates about 0.1 times their accretion rates, the wind can carry away enough angular momentum to keep the stars from being spun up unrealistically by accretion. This paper presents a preliminary set of theoretical models of accretiondriven winds from the polar regions of T Tauri stars. These models are based on recently published self-consistent simulations of the Sun’s coronal heating and wind acceleration. In addition to the convection-driven MHD turbulence (which dominates in the solar case), we add another source of wave energy at the photosphere that is driven by the impact of plasma in neighboring flux tubes undergoing magnetospheric accretion. This added energy, determined quantitatively from the far-field theory of MHD wave generation, is sufficient to produce T TauriYlike mass-loss rates of at least 0.01 times the accretion rate. While still about an order of magnitude below the level required for efficient angular momentum removal, these are the first self-consistent models of T Tauri winds that agree reasonably well with a range of observational mass-loss constraints. The youngest modeled stellar winds are supported by Alfvén wave pressure, they have low temperatures (‘‘extended chromospheres’’), and they are likely to be unstable to the formation of counterpropagating shocks and clumps far from the star.

Steven R. Cranmer

2008-01-01T23:59:59.000Z

87

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

E-Print Network (OSTI)

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.

Meyers, Johan

2012-01-01T23:59:59.000Z

88

Self-consistent Coronal Heating and Solar Wind Acceleration from Anisotropic Magnetohydrodynamic Turbulence  

E-Print Network (OSTI)

We present a series of models for the plasma properties along open magnetic flux tubes rooted in solar coronal holes, streamers, and active regions. These models represent the first self-consistent solutions that combine: (1) chromospheric heating driven by an empirically guided acoustic wave spectrum, (2) coronal heating from Alfven waves that have been partially reflected, then damped by anisotropic turbulent cascade, and (3) solar wind acceleration from gradients of gas pressure, acoustic wave pressure, and Alfven wave pressure. The only input parameters are the photospheric lower boundary conditions for the waves and the radial dependence of the background magnetic field along the flux tube. For a single choice for the photospheric wave properties, our models produce a realistic range of slow and fast solar wind conditions by varying only the coronal magnetic field. Specifically, a 2D model of coronal holes and streamers at solar minimum reproduces the latitudinal bifurcation of slow and fast streams seen by Ulysses. The radial gradient of the Alfven speed affects where the waves are reflected and damped, and thus whether energy is deposited below or above the Parker critical point. As predicted by earlier studies, a larger coronal ``expansion factor'' gives rise to a slower and denser wind, higher temperature at the coronal base, less intense Alfven waves at 1 AU, and correlative trends for commonly measured ratios of ion charge states and FIP-sensitive abundances that are in general agreement with observations. These models offer supporting evidence for the idea that coronal heating and solar wind acceleration (in open magnetic flux tubes) can occur as a result of wave dissipation and turbulent cascade. (abridged abstract)

Steven R. Cranmer; Adriaan A. van Ballegooijen; Richard J. Edgar

2007-03-13T23:59:59.000Z

89

Turbulence in the sub-Alfv\\'enic solar wind driven by reflection of low-frequency Alfv\\'en waves  

E-Print Network (OSTI)

We study the formation and evolution of a turbulent spectrum of Alfv\\'en waves driven by reflection off the solar wind density gradients, starting from the coronal base up to 17 solar radii, well beyond the Alfv\\'enic critical point. The background solar wind is assigned and 2D shell models are used to describe nonlinear interactions. We find that the turbulent spectra are influenced by the nature of reflected waves. Close to the base, these give rise to a flatter and steeper spectrum for the outgoing and reflected waves respectively. At higher heliocentric distance both spectra evolve toward an asymptotic Kolmogorov spectrum. The turbulent dissipation is found to account for at least half of the heating required to sustain the background imposed solar wind and its shape is found to be determined by the reflection-determined turbulent heating below 1.5 solar radii. Therefore reflection and reflection-driven turbulence are shown to play a key role in the accelerationof the fast solar wind and origin of the tur...

Verdini, A; Buchlin, E

2009-01-01T23:59:59.000Z

90

Numerical simulation to determine the effects of incident wind shear and turbulence level on the flow around a building  

Science Conference Proceedings (OSTI)

The effects of incident shear and turbulence on flow around a cubical building are being investigated by a turbulent kinetic energy/dissipation model (TEMPEST). The numerical simulations demonstrate significant effects due to the differences in the incident flow. The addition of upstream turbulence and shear results in a reduced size of the cavity directly behind the building. The accuracy of numerical simulations is verified by comparing the predicted mean flow fields with the available wind-tunnel measurements of Castro and Robins (1977). Comparing the authors' results with experimental data, the authors show that the TEMPEST model can reasonably simulate the mean flow.

Zhang, Y.Q.; Huber, A.H.; Arya, S.P.S.; Snyder, W.H.

1992-01-01T23:59:59.000Z

91

Co-existence of whistler waves with kinetic Alfven wave turbulence for the high-beta solar wind plasma  

SciTech Connect

It is shown that the dispersion relation for whistler waves is identical for a high or low beta plasma. Furthermore, in the high-beta solar wind plasma, whistler waves meet the Landau resonance with electrons for velocities less than the thermal speed, and consequently, the electric force is small compared to the mirror force. As whistlers propagate through the inhomogeneous solar wind, the perpendicular wave number increases through refraction, increasing the Landau damping rate. However, the whistlers can survive because the background kinetic Alfven wave (KAW) turbulence creates a plateau by quasilinear (QL) diffusion in the solar wind electron distribution at small velocities. It is found that for whistler energy density of only {approx}10{sup -3} that of the kinetic Alfven waves, the quasilinear diffusion rate due to whistlers is comparable to KAW. Thus, very small amplitude whistler turbulence can have a significant consequence on the evolution of the solar wind electron distribution function.

Mithaiwala, Manish; Crabtree, Chris; Ganguli, Gurudas [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375-5346 (United States); Rudakov, Leonid [Icarus Research Inc., P.O. Box 30780, Bethesda, Maryland 20824-0780 (United States)

2012-10-15T23:59:59.000Z

92

Measurement in a wind tunnel of the modification of mean wind and turbulence characteristics due to induction effects near wind turbine rotors  

DOE Green Energy (OSTI)

It is the purpose of this report to provide experimental data on the wind field surrounding a single model wind turbine rotor disk. These data should provide an improved physical insight into the induction effects of the air flow as it approaches the wind turbine. This insight should in turn improve an analytical model's predictive capabilities. A scaled model of a horizontal-axis wind turbine (a two-bladed rotor of diameter 53 cm) was placed into the Meteorological Wind Tunnel (MWT) facility at Colorado State University (cross-section width of 183 cm). Four different approach flow conditions were studied: low and moderate turbulence levels (0.1% and 1.5% intensity) at both 6 and 7.6 m/s freestream air velocities. For each of these flow conditions the rotor power coefficient versus tip speed ratio was obtained, and the 3-dimensional velocity field from 3 rotor diameters upwind to 0.5 diameter downwind was tabulated. The power output of the rotor was obtained via a simple prony brake friction device that imparts a torque (measured by the deflection of a spring) to the spinning shaft of the wind turbine. The rotor speed, measured by a strobe light, was observed to vary with load from 900 rpm up to 2100 rpm for the flow conditions described above. The 3-dimensional velocity field was measured via a three-hot-film probe. Details of the measurement techniques are provided. The test program and data results are also given. A short discussion of the implications of this data set is included. 12 refs., 19 figs., 11 tabs.

Neff, D.E.; Meroney, R.N.

1987-08-01T23:59:59.000Z

93

Wave-Turbulence interactions in the Upper Ocean. Part I: The Energy Balance of the Interacting Fields of Surface Wind Waves and Wind-Induced Three-Dimensional Turbulence  

Science Conference Proceedings (OSTI)

We analyze in detail the budget of total and fluctuating energy in the surface layer of the ocean. We suggest a rational scheme for separating the budget of turbulence from that of random wind-generated surface waves, and suggest in particular a ...

S. A. Kitaigorodskii; J. L. Lumley

1983-11-01T23:59:59.000Z

94

Wind Shear Enhancement of Entrainment and Refractive Index Structure Parameter at the Top of a Turbulent Mixed Layer  

Science Conference Proceedings (OSTI)

A model for inversion layer turbulence properties of a cloud-free entraining mixed-layer with wind shear at the top is developed. Using the approach of Wyngaard and LeMone (1980), expressions for the average values of ? and ?w2 in the entrainment ...

C. W. Fairall

1984-12-01T23:59:59.000Z

95

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

E-Print Network (OSTI)

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.

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

2000-03-08T23:59:59.000Z

96

DISTRIBUTION OF MAGNETIC DISCONTINUITIES IN THE SOLAR WIND AND IN MAGNETOHYDRODYNAMIC TURBULENCE  

Science Conference Proceedings (OSTI)

The statistical properties of magnetic discontinuities in the solar wind are investigated by measuring fluctuations in the magnetic field direction, given by the rotation {Delta}{theta} that the magnetic field vector undergoes during time interval {Delta}t. We show that the probability density function, P({Delta}{theta}), can be described by a simple model in which the magnetic field vector purely rotates with a relative increment {Delta}B/B that is lognormally distributed. We find that the probability density function of increments, P({Delta}B/B), has a remarkable scaling property: the normalized variable x = ({Delta}B/B) {center_dot} ({Delta}t/{Delta}t{sub 0}){sup -{alpha}} has a universal lognormal distribution for all time intervals {Delta}t. We then compare measurements from the solar wind with those from direct numerical simulations of magnetohydrodynamic (MHD) turbulence. We find good agreement for P({Delta}{theta}) obtained in the two cases when the magnetic guide field to fluctuations ratio B{sub 0}/b{sub rms} is chosen accordingly. However, the scale invariance of P({Delta}B/B) is broken in the MHD simulations with relatively limited inertial interval, which causes P({Delta}{theta}) to scale with measurement interval differently than in the solar wind.

Zhdankin, Vladimir; Boldyrev, Stanislav [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706 (United States); Mason, Joanne [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)

2012-12-01T23:59:59.000Z

97

Distribution of Magnetic Discontinuities in the Solar Wind and in MHD Turbulence  

E-Print Network (OSTI)

The statistical properties of magnetic discontinuities in the solar wind are investigated by measuring fluctuations in the magnetic field direction, given by the rotation Delta theta that the magnetic field vector undergoes during time interval Delta t. We show that the probability density function for rotations, P(Delta theta), can be described by a simple model in which the magnetic field vector rotates with a relative increment (Delta B)/B that is lognormally distributed. We find that the probability density function of increments, P((Delta B)/B), has a remarkable scaling property: the normalized variable x=[(Delta B)/B]*[(Delta t)/(Delta t_0)]^-a has a universal lognormal distribution for all time intervals Delta t. We then compare measurements from the solar wind with those from direct numerical simulations of magnetohydrodynamic (MHD) turbulence. We find good agreement for P(Delta theta) obtained in the two cases when the magnetic guide-field to fluctuations ratio B_0/b_rms is chosen accordingly. However, the scale invariance of P((Delta B)/B) is broken in the MHD simulations with relatively limited inertial interval, which causes P(Delta theta) to scale with measurement interval differently than in the solar wind.

Vladimir Zhdankin; Stanislav Boldyrev; Joanne Mason

2012-10-12T23:59:59.000Z

98

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

E-Print Network (OSTI)

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.

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

2013-01-01T23:59:59.000Z

99

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

Science Conference Proceedings (OSTI)

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.

Shergelashvili, Bidzina M.; Fichtner, Horst [Institut fuer Theoretische Physik IV, Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

2012-06-20T23:59:59.000Z

100

DIRECT NUMERICAL SIMULATION OF RADIATION PRESSURE-DRIVEN TURBULENCE AND WINDS IN STAR CLUSTERS AND GALACTIC DISKS  

SciTech Connect

The pressure exerted by the radiation of young stars may be an important feedback mechanism that drives turbulence and winds in forming star clusters and the disks of starburst galaxies. However, there is great uncertainty in how efficiently radiation couples to matter in these high optical depth environments. In particular, it is unclear what levels of turbulence the radiation can produce, and whether the infrared radiation trapped by the dust opacity can give rise to heavily mass-loaded winds. In this paper, we report a series of two-dimensional flux-limited diffusion radiation-hydrodynamics calculations performed with the code ORION in which we drive strong radiation fluxes through columns of dusty matter confined by gravity in order to answer these questions. We consider both systems where the radiation flux is sub-Eddington throughout the gas column, and those where it is super-Eddington at the midplane but sub-Eddington in the atmosphere. In the latter, we find that the radiation-matter interaction gives rise to radiation-driven Rayleigh-Taylor instability, which drives supersonic turbulence at a level sufficient to fully explain the turbulence seen in Galactic protocluster gas clouds, and to make a non-trivial contribution to the turbulence observed in starburst galaxy disks. However, the instability also produces a channel structure in which the radiation-matter interaction is reduced compared to time-steady analytic models because the radiation field is not fully trapped. For astrophysical parameters relevant to forming star clusters and starburst galaxies, we find that this effect reduces the net momentum deposition rate in the dusty gas by a factor of {approx}2-6 compared to simple analytic estimates, and that in steady state the Eddington ratio reaches unity and there are no strong winds. We provide an approximation formula, appropriate for implementation in analytic models and non-radiative simulations, for the force exerted by the infrared radiation field in this regime.

Krumholz, Mark R. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Thompson, Todd A., E-mail: krumholz@ucolick.org, E-mail: thompson@astronomy.ohio-state.edu [Department of Astronomy and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210-1173 (United States)

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

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

E-Print Network (OSTI)

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.

Nishino, Takafumi

2012-01-01T23:59:59.000Z

102

Turbulence  

NLE Websites -- All DOE Office Websites (Extended Search)

Turbulence Turbulence in Alcator C-Mod and Wendelstein 7-AS plasmas during controlled confinement transitions N.P.Basse, E.M.Edlund, C.L.Fiore, M.J.Greenwald, A.E.Hubbard, J.W.Hughes, J.H.Irby, G.J.Kramer 1 , L.Lin, Y.Lin, A.G.Lynn 2 , E.S.Marmar, D.R.Mikkelsen 1 , D.Mossessian, P.E.Phillips 2 , M.Porkolab, J.E.Rice, W.L.Rowan 2 , J.A.Snipes, J.L.Terry, S.M.Wolfe, S.J.Wukitch, K.Zhurovich, S.Zoletnik 3 and the C-Mod and W7-AS 4 Teams MIT Plasma Science and Fusion Center, Cambridge, USA 1 Princeton Plasma Physics Laboratory, Princeton, USA 2 University of Texas at Austin, Austin, USA 3 KFKI-RMKI, EURATOM Association, Budapest, Hungary 4 Max-Planck-Institut f¨ ur Plasmaphysik, EURATOM Association, Greifswald, Germany At certain values of the edge rotational transform, ι a = 1/q a , the confinement time of plasmas in the Wendelstein 7-AS (W7-AS) stellarator was found to

103

A comparison of predicted and observed turbulent wind fields present in natural and internal wind park environments  

DOE Green Energy (OSTI)

This paper assesses the accuracy of simulated wind fields for both the natural flow and that within a wind park environment. The simulated fields are compared with the observed ones in both the time and frequency domains. Actual measurements of the wind fields and the derived kinematic scaling parameters upwind and downwind of a large San Gorgonio Pass wind park are used. The deviations in the modeled wind field from the observed are discussed. 10 refs., 6 figs., 2 tabs.

Kelly, N D; Wright, A D

1991-10-01T23:59:59.000Z

104

An Airborne and Wind Tunnel Evaluation of a Wind Turbulence Measurement System for Aircraft-Based Flux Measurements  

Science Conference Proceedings (OSTI)

Although the ability to measure vertical eddy fluxes of gases from aircraft platforms represents an important capability to obtain spatially resolved data, accurate and reliable determination of the turbulent vertical velocity presents a great ...

K. E. Garman; K. A. Hill; P. Wyss; M. Carlsen; J. R. Zimmerman; B. H. Stirm; T. Q. Carney; R. Santini; P. B. Shepson

2006-12-01T23:59:59.000Z

105

Solar-wind turbulence and shear: a superposed-epoch analysis of corotating interaction regions at 1 AU  

Science Conference Proceedings (OSTI)

A superposed-epoch analysis of ACE and OMNI2 measurements is performed on 27 corotating interaction regions (CIRs) in 2003-2008, with the zero epoch taken to be the stream interface as determined by the maximum of the plasma vorticity. The structure of CIRs is investigated. When the flow measurements are rotated into the local-Parker-spiral coordinate system the shear is seen to be abrupt and intense, with vorticities on the order of 10{sup -5}-10{sup -4} sec{sup -1}. Converging flows perpendicular to the stream interface are seen in the local-Parker-spiral coordinate system and about half of the CIRs show a layer of divergent rebound flow away from the stream interface. Arguments indicate that any spreading of turbulence away from the region where it is produced is limited to about 10{sup 6} km, which is very small compared with the thickness of a CrR. Analysis of the turbulence across the CrRs is performed. When possible, the effects of discontinuities are removed from the data. Fluctuation amplitudes, the Alfvenicity, and the level of Alfvenic correlations all vary smoothly across the CrR. The Alfven ratio exhibits a decrease at the shear zone of the stream interface. Fourier analysis of 4.5-hr subintervals of ACE data is performed and the results are superposed averaged as an ensemble of realizations. The spectral slopes of the velocity, magnetic-field, and total-energy fluctuations vary smoothly across the CIR. The total-energy spectral slope is {approx} 3/2 in the slow and fast wind and in the CrRs. Analysis of the Elsasser inward-outward fluctuations shows a smooth transition across the CrR from an inward-outward balance in the slow wind to an outward dominance in the fast wind. A number of signatures of turbulence driving at the shear zone are sought (entropy change, turbulence amplitude, Alfvenicity, Alfven ratio, spectral slopes, in-out nature): none show evidence of driving of turbulence by shear.

Borovsky, Joseph E [Los Alamos National Laboratory; Denton, Michael H [LANCASTER UNIV.

2009-01-01T23:59:59.000Z

106

Advances in Fluid Modeling of the Solar Wind. Part 1: Electron and Anisotropic Proton Temperatures from the Collisionless Dissipation of Alfven Wave Turbulence  

E-Print Network (OSTI)

We develop a 1D solar-wind model that includes separate energy equations for the electrons and protons, proton temperature anisotropy, collisional and collisionless heat flux, and an analytical treatment of low-frequency, reflection-driven, Alfven-wave turbulence. To partition the turbulent heating between electron heating, parallel proton heating, and perpendicular proton heating, we employ results from the theories of linear wave damping and nonlinear stochastic heating. We account for mirror and oblique firehose instabilities by increasing the proton pitch-angle scattering rate when the proton temperature anisotropy exceeds the threshold for either instability. We numerically integrate the equations of the model forward in time until a steady state is reached, focusing on two fast-solar-wind-like solutions. These solutions are consistent with a number of observations, supporting the idea that Alfven-wave turbulence plays an important role in the origin of the solar wind.

Chandran, Benjamin D G; Quataert, Eliot; Bale, Stuart D

2011-01-01T23:59:59.000Z

107

INCORPORATING KINETIC PHYSICS INTO A TWO-FLUID SOLAR-WIND MODEL WITH TEMPERATURE ANISOTROPY AND LOW-FREQUENCY ALFVEN-WAVE TURBULENCE  

Science Conference Proceedings (OSTI)

We develop a one-dimensional solar-wind model that includes separate energy equations for the electrons and protons, proton temperature anisotropy, collisional and collisionless heat flux, and an analytical treatment of low-frequency, reflection-driven, Alfven-wave (AW) turbulence. To partition the turbulent heating between electron heating, parallel proton heating, and perpendicular proton heating, we employ results from the theories of linear wave damping and nonlinear stochastic heating. We account for mirror and oblique firehose instabilities by increasing the proton pitch-angle scattering rate when the proton temperature anisotropy exceeds the threshold for either instability. We numerically integrate the equations of the model forward in time until a steady state is reached, focusing on two fast-solar-wind-like solutions. These solutions are consistent with a number of observations, supporting the idea that AW turbulence plays an important role in the origin of the solar wind.

Chandran, Benjamin D. G.; Dennis, Timothy J. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Quataert, Eliot [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States); Bale, Stuart D., E-mail: benjamin.chandran@unh.edu, E-mail: tim.dennis@unh.edu, E-mail: eliot@astro.berkeley.edu, E-mail: bale@ssl.berkeley.edu [Physics Department and Space Sciences Laboratory, 311 Old LeConte Hall, University of California, Berkeley, CA 94720 (United States)

2011-12-20T23:59:59.000Z

108

Measurement of Clear-Air Gradients and Turbulence Properties with Radar Wind Profilers  

Science Conference Proceedings (OSTI)

An experiment comparing balloon and profiler observations was carried out to evaluate the capability of Doppler radar wind profilers to remotely measure useful meteorological quantities other than wind. The site chosen was in Southern California ...

E. E. Gossard; D. E. Wolfe; K. P. Moran; R. A. Paulus; K. D. Anderson; L. T. Rogers

1998-04-01T23:59:59.000Z

109

Petascale Simulations of Inhomogeneous Alfvén Turbulence in the Solar Wind  

NLE Websites -- All DOE Office Websites (Extended Search)

A snapshot of turbulent magnetic field lines (red) inside a coronal hole that expands from a small patch on the solar surface to 5 solar radii A snapshot of turbulent magnetic field lines (red) inside a coronal hole that expands from a small patch on the solar surface to 5 solar radii A snapshot of turbulent magnetic field lines (red) inside a coronal hole that expands from a small patch on the solar surface to 5 solar radii. Alfven waves (AW), launched by convective motions on the photosphere, propagate in the inhomogeneous Solar atmosphere producing primary reflected waves that interact non-linearly with the outward waves, driving a turbulent cascade. This cascade continues with secondary reflections in a very complex interplay between wave reflections and nonlinear interactions. Selected slices across the simulation domain show contours of plasma current, indicating the generation of small scale structures where the

110

Wind Mixing In a Turbulent Surface Layer in the Presence of a Horizontal Density Gradient  

Science Conference Proceedings (OSTI)

The effect of a horizontal density gradient of buoyancy on the turbulent kinetic energy budget of the surface mixed layer in the ocean is discussed. The combination of a horizontal buoyancy gradient and a vertical shear of the horizontal velocity ...

Johan Rodhe

1991-07-01T23:59:59.000Z

111

Lagrangian Coherent Structure Analysis of Terminal Winds Detected by Lidar. Part I: Turbulence Structures  

Science Conference Proceedings (OSTI)

The accurate real-time detection of turbulent airflow patterns near airports is important for safety and comfort in commercial aviation. In this paper, a method is developed to identify Lagrangian coherent structures (LCS) from horizontal lidar ...

Wenbo Tang; Pak Wai Chan; George Haller

2011-02-01T23:59:59.000Z

112

Near-Surface Turbulence and Thermal Structure in a Wind-Driven Sea  

Science Conference Proceedings (OSTI)

Ocean surface turbulence at high sea states is evaluated using heat as a naturally occurring passive tracer. A freely drifting instrument with a mechanically driven temperature profiler, fixed depth thermistors, and conductivity cells was used to ...

Johannes R. Gemmrich; David M. Farmer

1999-03-01T23:59:59.000Z

113

A Wind Tunnel Study of Turbulence Effects on the Scavenging of Aerosol Particles by Water Drops  

Science Conference Proceedings (OSTI)

Laboratory experiments are described where the effects of turbulence on the impaction scavenging of aerosol particles by water drops were investigated. During the experiments the drops were freely suspended at their terminal velocities in the ...

O. Vohl; S. K. Mitra; K. Diehl; G. Huber; S. C. Wurzler; K-L. Kratz; H. R. Pruppacher

2001-10-01T23:59:59.000Z

114

The Minimum Wind Speed for Sustainable Turbulence in the Nocturnal Boundary Layer  

Science Conference Proceedings (OSTI)

The collapse of turbulence in the nocturnal boundary layer is studied by means of a simple bulk model that describes the basic physical interactions in the surface energy balance. It is shown that for a given mechanical forcing, the amount of ...

B. J. H. Van de Wiel; A. F. Moene; H. J. J. Jonker; P. Baas; S. Basu; J. M. M. Donda; J. Sun; A. A. M. Holtslag

2012-11-01T23:59:59.000Z

115

Wind Direction Dependence of Atmospheric Boundary Layer Turbulence Parameters in the Urban Roughness Sublayer  

Science Conference Proceedings (OSTI)

A variety of atmospheric boundary layer parameters are examined as a function of wind direction in both urban and suburban settings in Oklahoma City, Oklahoma, derived from measurements during the Joint Urban 2003 field campaign. Heterogeneous ...

Cheryl Klipp

2007-12-01T23:59:59.000Z

116

Turbulence Spectra and Dissipation Rates in a Wind Tunnel Model of the Atmospheric Convective Boundary Layer  

Science Conference Proceedings (OSTI)

A model of the atmospheric convective boundary layer (CBL) is realized in the thermally stratified wind tunnel of the Institute of Hydrology and Water Resources, University of Karlsruhe. Further experimental results from this model are presented. ...

Rolf Kaiser; Evgeni Fedorovich

1998-02-01T23:59:59.000Z

117

Perpendicular Ion Heating by Low-Frequency Alfven-Wave Turbulence in the Solar Wind  

E-Print Network (OSTI)

We consider ion heating by turbulent Alfven waves (AWs) and kinetic Alfven waves (KAWs) with perpendicular wavelengths comparable to the ion gyroradius and frequencies smaller than the ion cyclotron frequency. When the turbulence amplitude exceeds a certain threshold, an ion's orbit becomes chaotic. The ion then interacts stochastically with the time-varying electrostatic potential, and the ion's energy undergoes a random walk. Using phenomenological arguments, we derive an analytic expression for the rates at which different ion species are heated, which we test by simulating test particles interacting with a spectrum of randomly phased AWs and KAWs. We find that the stochastic heating rate depends sensitively on the quantity epsilon = dv/vperp, where vperp is the component of the ion velocity perpendicular to the background magnetic field B0, and dv (dB) is the rms amplitude of the velocity (magnetic-field) fluctuations at the gyroradius scale. In the case of thermal protons, when epsilon eps1, the proton ...

Chandran, Benjamin D G; Rogers, Barrett N; Quataert, Eliot; Germaschewski, Kai

2010-01-01T23:59:59.000Z

118

Proton, Electron, and Ion Heating in the Fast Solar Wind from Nonlinear Coupling Between Alfvenic and Fast-Mode Turbulence  

E-Print Network (OSTI)

In the parts of the solar corona and solar wind that experience the fewest Coulomb collisions, the component proton, electron, and heavy ion populations are not in thermal equilibrium with one another. Observed differences in temperatures, outflow speeds, and velocity distribution anisotropies are useful constraints on proposed explanations for how the plasma is heated and accelerated. This paper presents new predictions of the rates of collisionless heating for each particle species, in which the energy input is assumed to come from magnetohydrodynamic (MHD) turbulence. We first created an empirical description of the radial evolution of Alfven, fast-mode, and slow-mode MHD waves. This model provides the total wave power in each mode as a function of distance along an expanding flux tube in the high-speed solar wind. Next we solved a set of cascade advection-diffusion equations that give the time-steady wavenumber spectra at each distance. An approximate term for nonlinear coupling between the Alfven and fas...

Cranmer, Steven R

2012-01-01T23:59:59.000Z

119

Analysis of CASES-99 Lidar and Turbulence Data in Support of Wind Turbine Effects: April 1, 2001 to Januay 31, 2003  

DOE Green Energy (OSTI)

The nocturnal low-level jet (LLJ) of the Great Plains of the central United States has been identified as a promising source of high-momentum wind flow for wind energy. The acceleration of the winds after sunset above the surface produces a jet profile in the wind velocity, with maximum speeds that often exceed 10 m s-1 or more at heights near 100 m or more. These high wind speeds are advantageous for wind energy generation. The high speeds aloft, however, also produce a region of high shear between the LLJ and the earth's surface, where the nocturnal flow is often calm or nearly so. This shear zone below the LLJ generates atmospheric waves and turbulence that can cause strong vibration in the turbine rotors. It has been suggested that these vibrations contribute to premature failures in large wind turbines, which, of course, would be a considerable disadvantage for wind energy applications. In October 1999, a field project called the Cooperative Atmosphere-Surface Exchange Study 1999 campaign, or CASES-99, was conducted in southeastern Kansas to study the nocturnal stable boundary layer. One of the instruments deployed during CASES-99 was the High-Resolution Doppler Lidar, a new scanning, remote-sensing, wind-mapping instrument.

Banta, R. M.

2003-06-01T23:59:59.000Z

120

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

SciTech Connect

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

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

2006-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

A Bulk Turbulent Air–Sea Flux Algorithm for High-Wind, Spray Conditions  

Science Conference Proceedings (OSTI)

Sensible and latent heat can cross the air–sea interface by two routes: as interfacial fluxes controlled by molecular processes right at the interface, and as spray fluxes from the surface of sea spray droplets. Once the 10-m wind speed over the ...

Edgar L. Andreas; P. Ola G. Persson; Jeffrey E. Hare

2008-07-01T23:59:59.000Z

122

Simulating the effect of access road route slection on wind farm construction  

Science Conference Proceedings (OSTI)

Wind energy as a power source is attractive alternative to fossil fuels. Wind farms are typically constructed in undeveloped rural areas with challenging topography. The lack of a paved road network leading to the site and within the site itself pose ...

Khaled Nassar; Mohamed El Masry; Hesham Osman

2010-12-01T23:59:59.000Z

123

PROTON, ELECTRON, AND ION HEATING IN THE FAST SOLAR WIND FROM NONLINEAR COUPLING BETWEEN ALFVENIC AND FAST-MODE TURBULENCE  

Science Conference Proceedings (OSTI)

In the parts of the solar corona and solar wind that experience the fewest Coulomb collisions, the component proton, electron, and heavy ion populations are not in thermal equilibrium with one another. Observed differences in temperatures, outflow speeds, and velocity distribution anisotropies are useful constraints on proposed explanations for how the plasma is heated and accelerated. This paper presents new predictions of the rates of collisionless heating for each particle species, in which the energy input is assumed to come from magnetohydrodynamic (MHD) turbulence. We first created an empirical description of the radial evolution of Alfven, fast-mode, and slow-mode MHD waves. This model provides the total wave power in each mode as a function of distance along an expanding flux tube in the high-speed solar wind. Next, we solved a set of cascade advection-diffusion equations that give the time-steady wavenumber spectra at each distance. An approximate term for nonlinear coupling between the Alfven and fast-mode fluctuations is included. For reasonable choices of the parameters, our model contains enough energy transfer from the fast mode to the Alfven mode to excite the high-frequency ion cyclotron resonance. This resonance is efficient at heating protons and other ions in the direction perpendicular to the background magnetic field, and our model predicts heating rates for these species that agree well with both spectroscopic and in situ measurements. Nonetheless, the high-frequency waves comprise only a small part of the total Alfvenic fluctuation spectrum, which remains highly two dimensional as is observed in interplanetary space.

Cranmer, Steven R.; Van Ballegooijen, Adriaan A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-08-01T23:59:59.000Z

124

EERE: Wind  

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

EERE: Buildings The U.S. Department of Energy funds R&D to develop wind energy. Learn about the DOE Wind Program, how to use wind energy and get financial incentives, and access...

125

Turbulence Regimes and Turbulence Intermittency in the Stable Boundary Layer during CASES-99  

Science Conference Proceedings (OSTI)

An investigation of nocturnal intermittent turbulence during the Cooperative Atmosphere–Surface Exchange Study in 1999 (CASES-99) revealed three turbulence regimes at each observation height: 1) regime 1, a weak turbulence regime when the wind ...

Jielun Sun; Larry Mahrt; Robert M. Banta; Yelena L. Pichugina

2012-01-01T23:59:59.000Z

126

Turbulent Velocity-Variance Profiles in the Stable Boundary Layer Generated by a Nocturnal Low-Level Jet  

Science Conference Proceedings (OSTI)

Profiles of mean winds and turbulence were measured by the High Resolution Doppler lidar in the strong-wind stable boundary layer (SBL) with continuous turbulence. The turbulence quantity measured was the variance of the streamwise wind velocity ...

Robert M. Banta; Yelena L. Pichugina; W. Alan Brewer

2006-11-01T23:59:59.000Z

127

Variations of Winds and Turbulence Seen by the 50-MHz Radar at White Sands Missile Range, New Mexico  

Science Conference Proceedings (OSTI)

The mean vertical profiles of the winds from about 5 to 20 km at White Sands Missile Range, New Mexico, are described. The variability of wind speed, spectral width, volume reflectivity calibrated as CN2, and vertical wind shear are documented as ...

G. D. Nastrom; F. D. Eaton

1995-10-01T23:59:59.000Z

128

Fluctuating wind power penetration as limited by frequency standard.  

E-Print Network (OSTI)

??Fluctuating wind power is due to wind turbulence and is the part which should be filtered out leaving behind the more predictable mean wind power… (more)

Luo, Changling, 1980-

2005-01-01T23:59:59.000Z

129

Effects of Atmospheric Turbulence on Ballistic Testing  

Science Conference Proceedings (OSTI)

The effects of atmospheric turbulence on munition target scatter are determined from numerical simulations of ballistic trajectories through many realizations of realistic simulated turbulent wind fields. A technique is evaluated for correcting ...

Rod Frehlich; Robert Sharman; Charles Clough; Michael Padovani; Kelly Fling; Ward Boughers; W. Scott Walton

2008-05-01T23:59:59.000Z

130

turbulence | OpenEI  

Open Energy Info (EERE)

turbulence turbulence Dataset Summary Description This raw data reflects readings from instruments mounted on or near a 82 meter meteorological tower located at the National Wind Technology Center (NWTC), approximately 5 miles south of Boulder, CO (specifically: 39.9107 N, 105.2348 W, datum WGS84). Source NREL Date Released Unknown Date Updated Unknown Keywords DOE irradiance NREL NWTC temperature turbulence wind wind direction wind speed Data text/plain icon Raw data (txt, 82 KiB) application/vnd.openxmlformats-officedocument.spreadsheetml.sheet icon Raw data field descriptions (xlsx, 52.5 KiB) Quality Metrics Level of Review Some Review Comment Data have not been reviewed for accuracy or completeness; disclaimer available (http://www.nrel.gov/disclaimer.html). Temporal and Spatial Coverage

131

Wind Tunnel Study of Turbulent Flow Structure in the Convective Boundary Layer Capped by a Temperature Inversion  

Science Conference Proceedings (OSTI)

Experiments on simulating the atmospheric convective boundary layer (CBL), capped by a temperature inversion and affected by surface shear, were carried out in the thermally stratified wind tunnel of the Institute of Hydrology and Water Resources,...

Evgeni Fedorovich; Rolf Kaiser; Matthias Rau; Erich Plate

1996-05-01T23:59:59.000Z

132

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

Science Conference Proceedings (OSTI)

Wind-induced near-inertial energy has been believed to be an important source for generating the ocean mixing required to maintain the global meridional overturning circulation. In the present study, the near-inertial energy budget in a realistic ...

Xiaoming Zhai; Richard J. Greatbatch; Carsten Eden; Toshiyuki Hibiya

2009-11-01T23:59:59.000Z

133

Modeling of Trade Wind Cumuli with a Low-Order Turbulence Model: Toward a Unified Description of Cu and Se Clouds in Meteorological Models  

Science Conference Proceedings (OSTI)

A simple method is proposed to extend a low-order turbulence scheme including a subgrid-scale cloudiness scheme to represent not only nonconvective (stratiform) cloudiness and turbulence but also shallow, nonprecipitating cumulus convection by ...

P. Bechtold; J. W. M. Cuijpers; P. Mascart; P. Trouilhet

1995-02-01T23:59:59.000Z

134

Controlling hour-long power of wind farms.  

E-Print Network (OSTI)

??In attempting to control the power output of a wind farm, it is first necessary to smooth the power fluctuations due to wind turbulence. This… (more)

Li, Pei, 1981-

2007-01-01T23:59:59.000Z

135

On the Fluid Dynamical Theory of Turbulent Gas Transfer Across an Air-Sea Interface in the Presence of Breaking Wind-Waves  

Science Conference Proceedings (OSTI)

It is shown that in order to describe the transfer of gases in the liquid near the air-sea interface, the vertical structure of three-dimensional small-scale turbulence in turbulent patches generated by breaking waves must be considered. The ...

S. A. Kitaigorodskii

1984-05-01T23:59:59.000Z

136

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

SciTech Connect

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.

Jeremy Firestone; Dawn Kurtz Crompton

2011-10-22T23:59:59.000Z

137

Turbulence Kinetic Energy Budget Profiles Derived from Doppler Sodar Measurements  

Science Conference Proceedings (OSTI)

Doppler sodar wind measurements made in light wind conditions in September 1979 near a power plant in Turbigo, Italy, are used to derive terms in the turbulence kinetic energy (TKE) budget. Measurements on five days are grouped into two classes: ...

Gary K. Greenhut; Giangiuseppe Mastrantonio

1989-02-01T23:59:59.000Z

138

Investigation of Flow, Turbulence, and Dispersion within Built Environments  

E-Print Network (OSTI)

Properties of the wind field within the Oklahoma City ParkProperties of the wind field within the Oklahoma City Parkwinds, turbulence, and dispersion in built-up downtown areas of Oklahoma

Pan, Hansheng

2011-01-01T23:59:59.000Z

139

Radar Wind Profiler Radial Velocity: A Comparison with Doppler Lidar  

Science Conference Proceedings (OSTI)

The accuracy of the radial wind velocity measured with a radar wind profiler will depend on turbulent variability and instrumental noise. Radial velocity estimates of a boundary layer wind profiler are compared with those estimated by a Doppler ...

Stephen A. Cohn; R. Kent Goodrich

2002-12-01T23:59:59.000Z

140

Mesoscale Influences of Wind Farms throughout a Diurnal Cycle  

Science Conference Proceedings (OSTI)

Large wind farms are expected to influence local and regional atmospheric circulations. Using a mesoscale parameterization of the effects of wind farms that includes a momentum sink and a wind speed–dependent source of turbulent kinetic energy, ...

Anna C. Fitch; Julie K. Lundquist; Joseph B. Olson

2013-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Example of Reduced Turbulence during Thunderstorm Outflow  

Science Conference Proceedings (OSTI)

The vertical structures of turbulence, winds, and temperatures are analyzed from a 92-m instrumented tower and a collocated acoustic sodar during an outflow episode from a weak thunderstorm over sloping terrain in northern New Mexico. Prior to ...

Brent M. Bowen

1996-06-01T23:59:59.000Z

142

Wind characteristics for agricultural wind energy applications  

SciTech Connect

Wind energy utilization in agriculture can provide a potentially significant savings in fuel oil consumption and ultimately a cost savings to the farmer. A knowledge of the wind characteristics within a region and at a location can contribute greatly to a more efficient and cost-effective use of this resource. Current research indicates that the important wind characteristics include mean annual wind speed and the frequency distribution of the wind, seasonal and diurnal variations in wind speed and direction, and the turbulent and gustiness characteristics of the wind. Further research is underway to provide a better definition of the total wind resource available, improved methods for siting WECS and an improved understanding of the environment to which the WECS respond.

Renne, D. S.

1979-01-01T23:59:59.000Z

143

Crop Wind Energy Experiment (CWEX): Observations of Surface-Layer, Boundary Layer, and Mesoscale Interactions with a Wind Farm  

Science Conference Proceedings (OSTI)

Perturbations of mean and turbulent wind characteristics by large wind turbines modify fluxes between the vegetated surface and the lower boundary layer. While simulations have suggested that wind farms could significantly change surface fluxes of heat, ...

Daniel A. Rajewski; Eugene S. Takle; Julie K. Lundquist; Steven Oncley; John H. Prueger; Thomas W. Horst; Michael E. Rhodes; Richard Pfeiffer; Jerry L. Hatfield; Kristopher K. Spoth; Russell K. Doorenbos

2013-05-01T23:59:59.000Z

144

The Turbulence Structure of Nocturnal Slope Flow  

Science Conference Proceedings (OSTI)

Measurements of the turbulence structure of nocturnal slope flow are used to test the hypothesis that slope flow turbulence in the region above the low-level wind maximum is decoupled from the surface and has a local structure similar to that ...

T. W. Horst; J. C. Doran

1988-02-01T23:59:59.000Z

145

WIND DATA REPORT Gardner NCCI  

E-Print Network (OSTI)

/RERL_Fact_Sheet_6_Wind_resource_interpretation.pdf * 1 m/s = 2.237 mph. SECTION 1 January 30, 2008 Renewable Energy, and wind roses are included in APPENDIX B. January 30, 2008 Renewable Energy Research Laboratory Page 8 ­ Turbulent Intensity vs. Wind Speed, March 1, 2007 ­ May 31, 2007 January 30, 2008 Renewable Energy Research

Massachusetts at Amherst, University of

146

Flashback, Blow out, Emissions and Turbulent Displacement Flame...  

NLE Websites -- All DOE Office Websites (Extended Search)

driving physics relating turbulent flame speeds to flashback at conditions relevant to gas turbine engines. Testing was conducted in an optically accessible single nozzle...

147

Comparison of Wind Profiler and Aircraft Wind Measurements at Chebogue Point, Nova Scotia  

Science Conference Proceedings (OSTI)

In August 1993, a 915-MHz boundary layer wind-profiling radar was deployed at Chebogue Point, Nova Scotia, to provide wind, turbulence, and boundary layer structure information for the North Atlantic Regional Experiment summer 1993 intensive ...

Wayne M. Angevine; J. Ian Macpherson

1995-04-01T23:59:59.000Z

148

Emergence of Jets from Turbulence in the Shallow-Water Equations on an Equatorial Beta Plane  

Science Conference Proceedings (OSTI)

Coherent jets, such as the Jovian banded winds, are a prominent feature of rotating turbulence. Shallow-water turbulence models capture the essential mechanism of jet formation, which is systematic eddy momentum flux directed up the mean velocity ...

Brian F. Farrell; Petros J. Ioannou

2009-10-01T23:59:59.000Z

149

Numerical Simulation of ANATEX Tracer Data Using a Turbulence Closure Model for Long-Range Dispersion  

Science Conference Proceedings (OSTI)

A long-range transport model based on turbulence closure concepts is described. The model extends the description of planetary boundary layer turbulent diffusion to the larger scales and uses statistical wind information to predict contaminant ...

R. I. Sykes; S. F. Parker; D. S. Henn; W. S. Lewellen

1993-05-01T23:59:59.000Z

150

Turbulence Structure of the Hurricane Boundary Layer between the Outer Rainbands  

Science Conference Proceedings (OSTI)

As part of the Coupled Boundary Layers Air–Sea Transfer (CBLAST)-Hurricane program, flights were conducted to directly measure turbulent fluxes and turbulence properties in the high-wind boundary layer of hurricanes between the outer rainbands. ...

Jun A. Zhang; William M. Drennan; Peter G. Black; Jeffrey R. French

2009-08-01T23:59:59.000Z

151

Calculation of Surface Fluxes under Convective Conditions by Turbulence Closure Models  

Science Conference Proceedings (OSTI)

A method of deriving new relationships between near-surface turbulent fluxes and vertical differences of wind speed and potential temperature between two levels in the atmospheric surface layer from simplified second-order turbulence closure ...

Lech ?obocki

2001-03-01T23:59:59.000Z

152

NREL: Learning - Wind Energy Basics: How Wind Turbines Work  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Energy Basics: How Wind Turbines Work Wind Energy Basics: How Wind Turbines Work We have been harnessing the wind's energy for hundreds of years. From old Holland to farms in the United States, windmills have been used for pumping water or grinding grain. Today, the windmill's modern equivalent-a wind turbine-can use the wind's energy to generate electricity. Wind turbines, like windmills, are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more aboveground, they can take advantage of the faster and less turbulent wind. Turbines catch the wind's energy with their propeller-like blades. Usually, two or three blades are mounted on a shaft to form a rotor. A blade acts much like an airplane wing. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure

153

LIDAR Wind Speed Measurements of Evolving Wind Fields  

DOE Green Energy (OSTI)

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.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

154

LIDAR Wind Speed Measurements of Evolving Wind Fields  

SciTech Connect

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.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

155

Wind Energy Assessment Study for Nevada -- Tall Tower Deployment (Stone Cabin): 26 June 2005 - 31 December 2007  

DOE Green Energy (OSTI)

The objective of this work effort was to characterize wind shear and turbulence for representative wind-developable areas in Nevada.

Koracin, D.; Reinhardt, R.; McCurdy, G.; Liddle, M.; McCord, T.; Vellore, R.; Minor, T.; Lyles, B.; Miller, D.; Ronchetti, L.

2009-12-01T23:59:59.000Z

156

RESEARCH ARTICLE Dynamic wind loads and wake characteristics of a wind turbine  

E-Print Network (OSTI)

RESEARCH ARTICLE Dynamic wind loads and wake characteristics of a wind turbine model of the unsteady vortex and turbulent flow structures in the near wake of a horizontal axis wind turbine model.e., aerodynamic forces and bending moments) acting on the wind turbine model by using a high-sensitive force

Hu, Hui

157

Towns across Massachusetts are considering wind power, not only because it is one of the cleanest,  

E-Print Network (OSTI)

of energy captured from the wind and electricity produced. The quality of a wind site depends on may things of the wind and create turbulence. Turbulence reduces the amount of energy that can be captured and can Power: Siting in Communities Wind Power on the Community Scale Renewable Energy Research Laboratory

Massachusetts at Amherst, University of

158

NREL Develops Simulations for Wind Plant Power and Turbine Loads...  

NLE Websites -- All DOE Office Websites (Extended Search)

loading due to wake turbulence. The current state of knowledge concerning wind turbine wakes and how they interact with other turbines and the atmospheric boundary layer is...

159

3D Simulation of a 5MW Wind Turbine.  

E-Print Network (OSTI)

??In the present work, the influence of turbulence and gravity forces on the tower and the rotor of a 5MW onshore wind turbine has been… (more)

Namiranian, Abtin

2011-01-01T23:59:59.000Z

160

NREL: Wind Research - Projects  

NLE Websites -- All DOE Office Websites (Extended Search)

Projects Projects NREL's wind energy research and development projects focus on reducing the cost of wind technology and expanding access to wind energy sites. Our specialized technical expertise, comprehensive design and analysis tools, and unique testing facilities help industry overcome challenges to bringing new wind technology to the marketplace. Some of these success stories are described in NREL's Wind R&D Success Stories. We also work closely with universities and other national laboratories supporting fundamental research in wind technologies, including aerodynamics, aeroacoustics, and material sciences essential in the development of new blade technologies and advanced controls, power electronics, and testing to further refine drivetrain topology.

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Wind energy information guide  

DOE Green Energy (OSTI)

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.

NONE

1996-04-01T23:59:59.000Z

162

Transilient Turbulence Theory. Part II: Turbulent Adjustment  

Science Conference Proceedings (OSTI)

Turbulent adjustment is a scheme where dynamic instabilities in the flow are eliminated by turbulence. It is a form of first-order turbulence closure that is applicable to numerical forecast models of the atmosphere. The responsive form of ...

Roland B. Stull; Takehiko Hasegawa

1984-12-01T23:59:59.000Z

163

An Objective Clear-Air Turbulence Forecasting Technique: Verification and Operational Use  

Science Conference Proceedings (OSTI)

An objective technique for forecasting clear-air turbulence (CAT) is described. An index is calculated based on the product of horizontal deformation and vertical wind shear derived from numerical model forecast winds aloft. The forecast ...

Gary P. Ellrod; David I. Knapp

1992-03-01T23:59:59.000Z

164

Estimators for the Standard Deviation of Horizontal Wind Direction  

Science Conference Proceedings (OSTI)

The standard deviation of horizontal wind direction is a central quantity in the description of atmospheric turbulence and of great practical use in dispersion models. As horizontal wind direction is a circular variable, its standard deviation ...

Rudolf O. Weber

1997-10-01T23:59:59.000Z

165

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

DOE Green Energy (OSTI)

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.

Not Available

2012-04-01T23:59:59.000Z

166

Comparison of Wind Monitoring Systems. Pad II: Doppley. Sodars  

Science Conference Proceedings (OSTI)

Measurements of wind speed, wind direction, and the vertical component of turbulence, from four different commercially available Doppler sodars, are compared with similar measurements from in situ sensors on a 300 m instrumented tower. Results ...

P. L. Finkelstein; J. C. Kaimal; J. E. Gaynor; M. E. Graves; T. J. Lockhart

1986-12-01T23:59:59.000Z

167

Solar and Wind Easements | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solar and Wind Easements Solar and Wind Easements Solar and Wind Easements < Back Eligibility Commercial Fed. Government Industrial Local Government Nonprofit Residential Schools State Government Savings Category Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Water Heating Wind Program Info State Montana Program Type Solar/Wind Access Policy Provider Montana Department of Environmental Quality Montana's solar and wind easement provisions allow property owners to create solar and wind easements for the purpose of protecting and maintaining proper access to sunlight and wind. Solar easements should be negotiated with neighboring property owners. Montana's solar easement law was enacted in 1979; the wind easement law was originally enacted in 1983.

168

LIDAR wind speed measurements of evolving wind fields  

E-Print Network (OSTI)

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. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios. Nomenclature a decay parameter for exponential coherence al decrement parameter for transverse coherence (l ? {u, v, w}) bl offset parameter for transverse coherence (l ? {u, v, w}) D longitudinal distance between two points or measurement preview distance F focal distance f frequency (Hz) ? LIDAR measurement angle off of longitudinal direction k wind velocity wavenumber (m?1) ? wavelength (m) R range along LIDAR beam r scan radius for spinning LIDAR scenario ri,j distance between two points in the yz plane U mean wind speed (m/s) ?i,j average mean wind speed between two points in the yz plane ? azimuth angle in the rotor plane ?2 xy(f) Coherence between signals x and y

Eric Simley; Lucy Y. Pao; Neil Kelley; Bonnie Jonkman; Rod Frehlich

2012-01-01T23:59:59.000Z

169

WIND DATA REPORT Ragged Mt Maine  

E-Print Network (OSTI)

Energy Research Laboratory (RERL) at the University of Massachusetts, Amherst. This report covers wind Average Wind Speeds, September 1, 2007 ­ November 30, 2007. January 22, 2008 Renewable Energy Research ­ Turbulence Intensity vs. Wind Speed, September 1, 2007 ­ November 30, 2007. January 22, 2008 Renewable Energy

Massachusetts at Amherst, University of

170

Resolved turbulence characteristics in large-eddy simulations nested within mesoscale simulations using the Weather Research and Forecasting model  

Science Conference Proceedings (OSTI)

One-way concurrent nesting within the Weather Research and Forecasting (WRF) model is examined for conducting large-eddy simulations (LES) nested within mesoscale simulations. Wind speed, spectra, and resolved turbulent stresses and turbulence ...

Jeff Mirocha; Branko Kosovi?; Gokhan Kirkil

171

Drag Anemometer Measurements of Turbulence over a Vegetated Surface  

Science Conference Proceedings (OSTI)

Turbulent fluctuations of vertical wind and fluxes of momentum, sensible heat and latent heat measured with a drag anemometer are compared to like data measured with other instruments. Means of the measured parameters agreed well with energy ...

T. Grayson Redford Jr.; Shashi B. Verma; Norman J. Rosenberg

1981-10-01T23:59:59.000Z

172

A Climatology of Turbulent Dispersion in the Troposphere  

Science Conference Proceedings (OSTI)

The authors present properties of turbulent, meridional mixing along isentropic surfaces within the troposphere. Twice-daily wind fields analyses from the European Centre for Medium-Range Weather Forecasts numerical weather prediction model for ...

Matthew Huber; James C. McWilliams; Michael Ghil

2001-08-01T23:59:59.000Z

173

ACCESS CONTROL  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

TERMSDEFINITIONS FROM DOE M 470.4-7 ACCESS CONTROL. The process of permitting access or denying access to information, facilities, nuclear materials, resources, or designated...

174

Wind resource assessment with a mesoscale non-hydrostatic model  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

175

Wind energy information directory  

DOE Green Energy (OSTI)

Wind Energy Information has been prepared to provide researchers, designers, manufacturers, distributors, dealers, and users of wind energy conversion systems with easy access to technical information. This directory lists organizations and publications which have the main objective of promoting the use of wind energy conversion systems, some organizations that can respond to requests for information on wind energy or make referrals to other sources of information, and some publications that occasionally include information on wind energy. The bibliography contains references to information for both the neophyte and the expert.

None

1979-10-01T23:59:59.000Z

176

Wind Stress and Heat Flux over the Ocean in Gale Force Winds  

Science Conference Proceedings (OSTI)

An offshore stable platform has been instrumented with wind turbulence, temperature and wave height sensors. Data from this platform have been analyzed by the eddy correlation method to obtain wind stress and heat flux at wind speeds from 6 to 22 ...

Stuart D. Smith

1980-05-01T23:59:59.000Z

177

Yaglom law in the expanding solar wind  

E-Print Network (OSTI)

We study the Yaglom law, which relates the mixed third order structure function to the average dissipation rate of turbulence, in a uniformly expanding solar wind by using the two scales expansion model of magnetohydrodynamic (MHD) turbulence. We show that due to the expansion of the solar wind two new terms appear in the Yaglom law. The first term is related to the decay of the turbulent energy by nonlinear interactions, whereas the second term is related to the non-zero cross-correlation of the Els\\"asser fields. Using magnetic field and plasma data from WIND and Helios 2 spacecrafts, we show that at lower frequencies in the inertial range of MHD turbulence the new terms become comparable to Yaglom's third order mixed moment, and therefore they cannot be neglected in the evaluation of the energy cascade rate in the solar wind.

Gogoberidze, G; Carbone, V

2013-01-01T23:59:59.000Z

178

Formation of Jets by Baroclinic Turbulence  

Science Conference Proceedings (OSTI)

Turbulent fluids are frequently observed to spontaneously self-organize into large 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 ...

Brian F. Farrell; Petros J. Ioannou

2008-11-01T23:59:59.000Z

179

ENERGETIC PARTICLE DIFFUSION IN STRUCTURED TURBULENCE  

Science Conference Proceedings (OSTI)

In the full-orbit particle simulations of energetic particle transport in plasmas, the plasma turbulence is typically described as a homogeneous superposition of linear Fourier modes. The turbulence evolution is, however, typically a nonlinear process, and, particularly in the heliospheric context, the solar wind plasma is inhomogeneous due to the transient structures, as observed by remote and in situ measurements. In this work, we study the effects of the inhomogeneities on energetic particle transport by using spatially distributed, superposed turbulence envelopes. We find that the cross-field transport is significantly reduced, when compared to the results obtained with homogeneous turbulence. The reduction can reach an order of magnitude when the enveloping breaks the wave phase coherence along the mean magnetic field direction.

Laitinen, T.; Dalla, S.; Kelly, J. [Jeremiah Horrocks Institute, University of Central Lancashire, PR1 2HE Preston (United Kingdom)

2012-04-20T23:59:59.000Z

180

TURBULENT FRBRNNING MVK130 Turbulent Combustion  

E-Print Network (OSTI)

TURBULENT F�RBR�NNING MVK130 Turbulent Combustion Poäng: 3.0 Betygskala: TH Valfri för: M4 to combustion, McGraw-Hill 1996. #12;

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Scientific Access  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientific Access The APS is a open user facility that makes beam time available to the international scientific community through a peer-reviewed proposal process. Two access...

182

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

SciTech Connect

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.

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

1984-09-01T23:59:59.000Z

183

Wind Easements | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Wind Easements Wind Easements Wind Easements < Back Eligibility Agricultural Fed. Government Institutional Local Government Nonprofit Residential Schools State Government Tribal Government Savings Category Wind Buying & Making Electricity Program Info State North Dakota Program Type Solar/Wind Access Policy North Dakota allows property owners to grant an easement that ensures adequate exposure of a wind-energy system to the wind. The easement runs with the land benefited and burdened, and terminates upon the conditions stated in the easement. The statutes authorizing the creation of wind easements include several provisions to protect property owners. For example, a wind easement may not make the property owner liable for any property tax associated with the wind-energy system or other equipment

184

Wind Powering America Podcasts, Wind Powering America (WPA)  

SciTech Connect

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.

Not Available

2012-04-01T23:59:59.000Z

185

Modeling wind forcing in phase resolving simulation of nonlinear wind waves  

E-Print Network (OSTI)

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 ...

Kalmikov, Alexander G

2010-01-01T23:59:59.000Z

186

Solar and Wind Easements and Local Option Rights Laws  

Energy.gov (U.S. Department of Energy (DOE))

Nebraska's solar and wind easement provisions allow property owners to create binding solar and wind easements for the purpose of protecting and maintaining proper access to sunlight and wind. ...

187

The Wind Project Development Process  

Wind Powering America (EERE)

Wind Project Wind Project Development Process Developed for the National Renewable Energy Laboratory by Dale Osborn Distributed Generation Systems, Inc. September 1998 The Wind Project Development Process Site Selection Land Agreements Wind Assessment Environmental Review Economic Modeling Interconnection Studies Financing Permitting Sales Agreements Turbine Procurement Construction Contracting Operations & Maintenance Site Selection Evidence of Significant Wind Preferably Privately Owned Remote Land Proximity to Transmission Lines Reasonable Road Access Few Environmental Concerns Receptive Community Land Agreements Term: Expected Life of the Turbine Assignable Indemnification Rights Compensation: Percentage of Revenues Reclamation Provision Wind Rights, Ingress/Egress Rights, Transmission Rights

188

Open Access  

NLE Websites -- All DOE Office Websites (Extended Search)

Communication » Communication » Open Access Open Access Open access (OA) is the practice of providing unrestricted access via the Internet to peer-reviewed scholarly journal articles. Learn more below... Questions? Open Access Email Open access publishing and publications have experienced substantial growth, expansion and uptake in recent years. What exactly is an open access publication? There are many definitions, but in a nutshell an open access publication is a publication that provides immediately free online access to all users worldwide. This may sound like a tall order, and yet there are to date over 4000 journal publications that fit this definition. The need for this type of access has been driven by the out-of-control costs for scholarly publications. Statistics kept by the Association for Research Libraries

189

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

SciTech Connect

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.

Clifton, A.

2012-12-01T23:59:59.000Z

190

Real-Time Ocean Wind Vector Retrieval from Marine Radar Image Sequences Acquired at Grazing Angle  

Science Conference Proceedings (OSTI)

This paper proposes a novel algorithm for retrieving the ocean wind vector from marine radar image sequences in real time. It is presented as an alternative to mitigate anemometer problems, such as blockage, shadowing, and turbulence. Since wind ...

Raul Vicen-Bueno; Jochen Horstmann; Eric Terril; Tony de Paolo; Jens Dannenberg

2013-01-01T23:59:59.000Z

191

Model-Simulated Influences of Shelterbelt Shape on Wind-Sheltering Efficiency  

Science Conference Proceedings (OSTI)

The authors report results of a numerical model used to simulate wind and turbulence fields for porous, living shelterbelts with seven different cross-sectional shapes. The simulations are consistent with results of Woodruff and Zingg whose wind-...

Hao Wang; E. S. Takle

1997-06-01T23:59:59.000Z

192

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

E-Print Network (OSTI)

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 ...

Malherbe, Gerard Andre

1976-01-01T23:59:59.000Z

193

NREL researchers are the first to use a high-performance com-puting tool for a large-eddy simulation of an entire wind plant.  

E-Print Network (OSTI)

an existing wind plant, augmenting previous studies of wind plant subsets. Wind turbines extract energy from the wind's flow, and as a byproduct they create a wake that trails behind them. If wind turbines mechanical loading due to wake turbulence.The current state of knowledge concerning wind turbine wakes

194

Linear Wind Farm Layout Optimization through Computational Intelligence  

Science Conference Proceedings (OSTI)

The optimal positioning of wind turbines, even in one dimension, is a problem with no analytical solution. This article describes the application of computational intelligence techniques to solve this problem. A systematic analysis of the optimal positioning ... Keywords: Far Wake Effects, Genetic Algorithms, Optimization, Simulated Annealing, Sitting, Turbulence and Roughness Length, Wind Farm Layout, Wind Turbines

José-Francisco Herbert-Acero; Jorge-Rodolfo Franco-Acevedo; Manuel Valenzuela-Rendón; Oliver Probst-Oleszewski

2009-11-01T23:59:59.000Z

195

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA  

E-Print Network (OSTI)

Distributions Figure 3 ­ Wind Speed Distribution, March 1, 2007 ­ May 31, 2007 July 16, 2007 Renewable Energy Figure 5 ­ Diurnal Wind Speeds, March 1, 2007 ­ May 31, 2007 July 16, 2007 Renewable Energy Research ­ Turbulence Intensity vs. Wind Speed, March 1, 2007 ­ May 31, 2007 July 16, 2007 Renewable Energy Research

Massachusetts at Amherst, University of

196

Resolving Difficult Issues Of Wind Power Micrositing In Complex  

E-Print Network (OSTI)

Micrositing of wind turbines in complex terrain is tricky game, and many of the current siting methods and tools, while useful and improving, remain inadequate to the task in extreme terrain. As a consequence, there are numerous wind turbine installations that are buffeted by damaging turbulence or are faced with suboptimal wind energy performance.

Terrain Session Resource; Russell G. Derickson A; Michael Mcdiarmid B; Brad C. Cochran C; Jon A. Peterka D; Russell G. Derickson A; Michael Mcdiarmid B; Brad C. Cochran C; Jon A. Peterka D

2004-01-01T23:59:59.000Z

197

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-R-1239(EN) 3 Contents 1 Introduction 5 2 The Department of Wind Energy and Atmospheric Physics 5 3

198

Analysis of Wind Speed Measurements using Continuous Wave LIDAR for Wind Turbine Control ?†  

E-Print Network (OSTI)

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 accurate the incoming wind field can be measured. This study examines the accuracy of different measurement scenarios that rely on coherent continuouswave Doppler LIDAR systems to determine their applicability to feedforward 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. Nomenclature d measurement preview distance F focal distance k wind velocity wavenumber (m?1) r scan radius for spinning LIDAR RMS root mean square ?u standard deviation of u component of wind velocity TI turbulence intensity ? LIDAR measurement angle ? mean u wind speed u ? friction velocity U ? D average friction velocity over rotor disk ? angle between laser and wind velocity vector ? angle in the rotor plane ? rotational rate of spinning LIDAR

Eric Simley; Lucy Y. Pao; Rod Frehlich; Bonnie Jonkman; Neil Kelley

2011-01-01T23:59:59.000Z

199

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

DOE Green Energy (OSTI)

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.

George, R.L.

1984-02-01T23:59:59.000Z

200

LIDAR Wind Speed Measurements of Evolving Wind Fields  

Science Conference Proceedings (OSTI)

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 that are 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 the validity of physicist G.I. Taylor's 1938 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 using the National Renewable Energy Laboratory's (NREL's) 5-megawatt turbine model to create a more realistic measurement model. A simple model of wind evolution was applied to a frozen wind field that was used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements were also evaluated using a large eddy simulation (LES) of a stable boundary layer that was provided by the National Center for Atmospheric Research. The LIDAR measurement scenario investigated consists of a hub-mounted LIDAR that scans a circle of points upwind of the turbine in order to estimate the wind speed component in the mean wind direction. Different combinations of the preview distance that is located upwind of the rotor and the radius of the scan circle were analyzed. It was found that the dominant source of measurement error for short preview distances is the detection of transverse and vertical wind speeds from the line-of-sight LIDAR measurement. It was discovered in previous studies that, in the absence of wind evolution, the dominant source of error for large preview distances is the spatial averaging caused by the LIDAR's sampling volume. However, by introducing wind evolution, the dominant source of error for large preview distances was found to be the coherence loss caused by evolving turbulence. Different measurement geometries were compared using the bandwidth for which the measurement coherence remained above 0.5 and also the area under the measurement coherence curve. Results showed that, by increasing the intensity of wind evolution, the measurement coherence decreases. Using the coherence bandwidth metric, the optimal preview distance for a fixed-scan radius remained almost constant for low and moderate amounts of wind evolution. For the wind field with the simple wind evolution model introduced, the optimal preview distance for a scan radius of 75% blade span (47.25 meters) was found to be 80 meters. Using the LES wind field, the optimal preview distance was 65 meters. When comparing scan geometries using the area under the coherence curve, results showed that, as the intensity of wind evolution increases, the optimal preview distance decreases.

Simley, E.; Pao, L. Y.; Kelley, N.; Jonkman, B.; Frehlich, R.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Airborne Wind Turbine  

Science Conference Proceedings (OSTI)

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.

None

2010-09-01T23:59:59.000Z

202

Applications of WiMAX-based wireless mesh network in monitoring wind farms  

Science Conference Proceedings (OSTI)

This paper has studied the feasibility of applying World Interoperability for Microwave Access (WiMAX) based Wireless Mesh Networks (WMNs) in monitoring wind farms. WMNs provide a dynamic topology which meets the requirements of communications ... Keywords: WMNs, WiMAX, World Interoperability for Microwave Access, communications, renewable energy, simulation, wind energy, wind farm monitoring, wind farms, wind power, wireless mesh networks, wireless networks

Gang Zheng; Hongbing Xu; Xinheng Wang; Jianxiao Zou

2010-09-01T23:59:59.000Z

203

Turbulent flow in graphene  

E-Print Network (OSTI)

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.

Kumar S. Gupta; Siddhartha Sen

2009-11-03T23:59:59.000Z

204

Extreme Winds and Wind Effects on Structures  

Science Conference Proceedings (OSTI)

Extreme Winds and Wind Effects on Structures. The Engineering ... section. I. Extreme Winds: ... II. Wind Effects on Buildings. Database ...

2013-01-17T23:59:59.000Z

205

TURBULENT FRBRNNING MVK 130 Turbulent Combustion  

E-Print Network (OSTI)

TURBULENT F�RBR�NNING MVK 130 Turbulent Combustion Antal poäng: 3.0. Valfri för: M4. Kursansvarig program med hänsyn till de modeller som används. Litteratur S.R. Turns: An introduction to combustion, Mc

206

Gyrokinetic turbulence: a nonlinear route to dissipation through phase space  

E-Print Network (OSTI)

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.

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

2008-06-05T23:59:59.000Z

207

Quantum Gravity and Turbulence  

E-Print Network (OSTI)

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.

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

2010-05-18T23:59:59.000Z

208

On apparent temperature in low-frequency Alfvenic turbulence  

SciTech Connect

Low-frequency, parallel propagating Alfvenic turbulence in collisionless plasmas is theoretically studied. Alfvenic turbulence is derived as an equilibrium state (Beltrami field) in the magnetohydrodynamic equations with the pressure anisotropy and multi-species of ions. It is shown that the conservation of the total 'apparent temperature' corresponds to the Bernoulli law. A simple model of the radially expanding solar wind including Alfvenic turbulence is also discussed. The conversion of the wave energy in the 'apparent temperature' into the 'real temperature' is facilitated with increasing radial distance.

Nariyuki, Yasuhiro [Faculty of Human Development, University of Toyama, 3190, Toyama City, Toyama 930-8555 (Japan)

2012-08-15T23:59:59.000Z

209

Influence of a New Turbulence Regime on the Global Air–Sea Heat Fluxes  

Science Conference Proceedings (OSTI)

Recent research has found that boundary layer turbulence changes its organization as the stratification approaches neutral from the unstable side. When the thermal forcing weakens in combination with wind speed above approximately 10 m s?1, ...

Erik Sahlée; Ann-Sofi Smedman; Anna Rutgersson; Ulf Högström

2008-11-01T23:59:59.000Z

210

The Influence of Whitecapping Waves on the Vertical Structure of Turbulence in a Shallow Estuarine Embayment  

Science Conference Proceedings (OSTI)

The vertical distribution of the turbulent kinetic energy dissipation rate was measured using an array of four acoustic Doppler velocimeters in the shallow embayment of Grizzly Bay, San Francisco Bay, California. Owing to the combination of wind ...

Nicole L. Jones; Stephen G. Monismith

2008-07-01T23:59:59.000Z

211

Turbulent Fluxes in the Hurricane Boundary Layer. Part II: Latent Heat Flux  

Science Conference Proceedings (OSTI)

As part of the recent ONR-sponsored Coupled Boundary Layer Air–Sea Transfer (CBLAST) Departmental Research Initiative, an aircraft was instrumented to carry out direct turbulent flux measurements in the high wind boundary layer of a hurricane. ...

William M. Drennan; Jun A. Zhang; Jeffrey R. French; Cyril McCormick; Peter G. Black

2007-04-01T23:59:59.000Z

212

Equilibrium Geostrophic Turbulence I: A Reference Solution in a ?-Plane Channel  

Science Conference Proceedings (OSTI)

A numerical solution is calculated for quasi-geostrophic, adiabatic, baroclinic, wind-driven flow in a ? channel. The rates of driving and dissipation are such that the solution is turbulent in equilibrium. The equilibrium state is characterized ...

James C. McWilliams; Julianna H. S. Chow

1981-07-01T23:59:59.000Z

213

Doppler Lidar Measurements of Turbulent Structure Function over an Urban Area  

Science Conference Proceedings (OSTI)

Analysis of radial wind velocity data from the Salford pulsed Doppler infrared lidar is used to calculate turbulent spectral statistics over the city of Salford in the United Kingdom. The results presented here, first, outline the error ...

F. Davies; C. G. Collier; G. N. Pearson; K. E. Bozier

2004-05-01T23:59:59.000Z

214

An Algorithm for Forecasting Mountain Wave–Related Turbulence in the Stratosphere  

Science Conference Proceedings (OSTI)

A global mountain wave parameterization for prediction of wave-related displacements and turbulence is described. The parameterization is used with input from National Meteorological Center analyses of wind and temperature to examine small-scale ...

Julio T. Bacmeister; Paul A. Newman; Bruce L. Gary; K. Roland Chan

1994-06-01T23:59:59.000Z

215

Distributed Wind | Open Energy Information  

Open Energy Info (EERE)

Distributed Wind Distributed Wind Jump to: navigation, search Distributed wind energy systems provide clean, renewable power for on-site use and help relieve pressure on the power grid while providing jobs and contributing to energy security for homes, farms, schools, factories, private and public facilities, distribution utilities, and remote locations.[1] Resources Clean Energy States Alliance. (2010). State-Based Financing Tools to Support Distributed and Community Wind Projects. Accessed September 27, 2013. This guide reviews the financing role that states, and specifically state clean energy funds, have played and can play in supporting community and distributed wind projects. Clean Energy States Alliance. (May 2010). Supporting Onsite Distributed Wind Generation Projects. Accessed September 27, 2013.

216

Open Access  

E-Print Network (OSTI)

© 2007 Brewer; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License

Earl J Brewer; Earl J Brewer

2007-01-01T23:59:59.000Z

217

Wave Breaking Dissipation in a Young Wind Sea  

Science Conference Proceedings (OSTI)

Coupled in situ and remote sensing measurements of young, strongly-forced, wind waves are applied to assess the role of breaking in an evolving wavefield. In situ measurements of turbulent energy dissipation from wave-following “SWIFT” drifters ...

Michael Schwendeman; Jim Thomson; Johannes R. Gemmrich

218

Modeling Compressed Turbulence  

Science Conference Proceedings (OSTI)

From ICE to ICF, the effect of mean compression or expansion is important for predicting the state of the turbulence. When developing combustion models, we would like to know the mix state of the reacting species. This involves density and concentration fluctuations. To date, research has focused on the effect of compression on the turbulent kinetic energy. The current work provides constraints to help development and calibration for models of species mixing effects in compressed turbulence. The Cambon, et al., re-scaling has been extended to buoyancy driven turbulence, including the fluctuating density, concentration, and temperature equations. The new scalings give us helpful constraints for developing and validating RANS turbulence models.

Israel, Daniel M. [Los Alamos National Laboratory

2012-07-13T23:59:59.000Z

219

NREL: Renewable Resource Data Center - Wind Resource Information  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Resource Information Wind Resource Information Photo of five wind turbines at the Nine Canyon Wind Project. The Nine Canyon Wind Project in Benton County, Washington, includes 37 wind turbines and 48 MW of capacity. Detailed wind resource information can be found on NREL's Wind Research Web site. This site provides access to state and international wind resource maps. Wind Integration Datasets are provided to help energy professionals perform wind integration studies and estimate power production from hypothetical wind plants. In addition, RReDC offers Meteorological Field Measurements at Potential and Actual Wind Turbine Sites and a Wind Energy Resource Atlas of the United States. Wind resource maps are also available from the NREL Dynamic Maps, GIS Data, and Analysis Tools Web site.

220

MHD Turbulence Revisited  

E-Print Network (OSTI)

Kraichnan (1965) proposed that MHD turbulence occurs as a result of collisions between oppositely directed Alfvén wave packets. Recent work has generated some controversy over the nature of non linear couplings between colliding Alfvén waves. We find that the resolution to much of the confusion lies in the existence of a new type of turbulence, intermediate turbulence, in which the cascade of energy in the inertial range exhibits properties intermediate between those of weak and strong turbulent cascades. Some properties of intermediate MHD turbulence are: (i) in common with weak turbulent cascades, wave packets belonging to the inertial range are long lived; (ii) however, components of the strain tensor are so large that, similar to the situation in strong turbulence, perturbation theory is not applicable; (iii) the breakdown of perturbation theory results from the divergence of neighboring field lines due to wave packets whose perturbations in velocity and magnetic fields are localized, but whose perturba...

Goldreich, P

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

SciTech Connect

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.

Wharton, S; Lundquist, J K

2010-02-22T23:59:59.000Z

222

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

SciTech Connect

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.

Wharton, S; Lundquist, J K

2010-02-22T23:59:59.000Z

223

ACCESS CONTROL  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

TERMS/DEFINITIONS FROM DOE M 470.4-7 TERMS/DEFINITIONS FROM DOE M 470.4-7 ACCESS CONTROL. The process of permitting access or denying access to information, facilities, nuclear materials, resources, or designated security areas. ACCESS CONTROL MEASURES. Hardware and software features, physical controls, operating procedures, administrative procedures, and various combinations of these designed to detect or prevent unauthorized access to classified information; special nuclear materials; Government property; automated information systems, facilities, or materials; or areas containing the above and to enforce use of these measures to protect Departmental security and property interests. CRITICAL PATH SCENARIO. An adversary-based scenario that is generated during the conduct of a vulnerability assessment and accounts for adversary tactics that

224

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

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.

Martin Wilde, Principal Investigator

2012-12-31T23:59:59.000Z

225

WIND ENERGY Wind Energ. (2012)  

E-Print Network (OSTI)

WIND ENERGY Wind Energ. (2012) Published online in Wiley Online Library (wileyonlinelibrary since energy production depends non-linearly on wind speed (U ), and wind speed observa- tions for the assessment of future long-term wind supply A. M. R. Bakker1 , B. J. J. M. Van den Hurk1 and J. P. Coelingh2 1

Haak, Hein

226

Siting Wind Energy | Open Energy Information  

Open Energy Info (EERE)

Siting Wind Energy Siting Wind Energy Jump to: navigation, search Wind turbines at the Forward Wind Energy Center in Fond du Lac and Dodge Counties, Wisconsin. Photo from Ruth Baranowski/NREL, NREL 21207 The following resources provide information about siting wind energy projects. Some are specific to a state or region but may still contain information applicable to other areas. Wind project siting tools, such as calculators and databases, can be found here. Resources American Wind Energy Association. (Updated 2011). Siting, Health, and the Environment. Accessed August 13, 2013. This fact sheet provides an overview of siting myths and facts. Environmental Law Institute. Siting Wind Energy Facilities: What Do Local Elected Officials Need to Know?. Accessed November 29, 2013.

227

The evaluation of a turbulent loads characterization system  

DOE Green Energy (OSTI)

In this paper we discuss an on-line turbulent load characterization system that has been designed to acquire loading spectra from turbines of the same design operating in several different environments and from different turbine designs operating in the same environment. This System simultaneously measures the rainflow-counted alternating and mean loading spectra and the hub-height turbulent mean shearing stress and atmospheric stability associated with the turbulent inflow. We discuss the theory behind the measurement configuration and the results of proof-of-concept testing recently performed at the National Wind Technology Center (NWTC) using a Bergey EXCEL-S 10-kW wind turbine. The on-line approach to characterizing the load spectra and the inflow turbulent scaling parameter produces results that are consistent with other measurements. The on-line approximation of the turbulent shear stress or friction velocity u* also is considered adequate. The system can be used to characterize turbulence loads during turbine deployment in a wide variety of environments. Using the WISPER protocol, we found that a wide-range, variable-speed turbine will accumulate a larger number of stress cycles in the low-cycle, high-amplitude (LCHA) region when compared with a constant speed rotor under similar inflow conditions.

Kelley, N.D.; McKenna, H.E. [National Renewable Energy Lab., Golden, CO (United States)

1996-01-01T23:59:59.000Z

228

Spectral Wave–Turbulence Decomposition  

Science Conference Proceedings (OSTI)

A new method of wave–turbulence decomposition is introduced, for which the only instrument required is one high-frequency pointwise velocity sensor. This is a spectral method that assumes equilibrium turbulence and no wave–turbulence interaction. ...

Jeremy D. Bricker; Stephen G. Monismith

2007-08-01T23:59:59.000Z

229

Radiosonde measurements of turbulence  

NLE Websites -- All DOE Office Websites (Extended Search)

at Cranwell, Lincolnshire, W. H. Pick and G. A. Bull, 1926. 3 Talk structure * Geomagnetic sensors to measure orientation * Orientation variability as a turbulence measure *...

230

An Analysis of Low-Frequency Maritime Atmospheric Turbulence  

Science Conference Proceedings (OSTI)

New data are presented for the spectrum of turbulent wind energy under maritime conditions in the frequency region 1.0–0.03 mHz. The corresponding measurements were made at five levels on a mast 46 m high on a small islet off the coast of central ...

Johannes Gjerstad; Svein Erik Aasen; Helge I. Andersson; Iver Brevik; Jørgen Løvseth

1995-08-01T23:59:59.000Z

231

Kinematics of Turbulence Convected by a Random Wave Field  

Science Conference Proceedings (OSTI)

Turbulent velocity spectra measured beneath wind waves show a large enhancement about the central wave frequency. A “5/3" frequency dependence can be seen both above and below the central peak, but with an apparent increase in spectral density at ...

J. L. Lumley; E. A. Terray

1983-11-01T23:59:59.000Z

232

Viscous Dissipation of Turbulence Kinetic Energy in Storms  

Science Conference Proceedings (OSTI)

In this note the magnitude of the viscous dissipation of turbulence kinetic energy in the surface layer of storms is investigated. It is shown that the layer-integrated dissipative heating is a cubic function of the wind speed. The magnitude of ...

Steven Businger; Joost A. Businger

2001-12-01T23:59:59.000Z

233

Near-Surface Turbulence in the Presence of Breaking Waves  

Science Conference Proceedings (OSTI)

Observations with a three-axis pulse-to-pulse coherent acoustic Doppler profiler and acoustic resonators reveal the turbulence and bubble field beneath breaking waves in the open ocean at wind speeds up to 14 m s?1. About 55%–80% of velocity ...

Johannes R. Gemmrich; David M. Farmer

2004-05-01T23:59:59.000Z

234

Near-Neutral Surface Layer Turbulence at the Boulder Atmospheric Observatory Tower: Evidence of Increasing Vertical Turbulence with Height  

Science Conference Proceedings (OSTI)

Wind and turbulence profiles were analyzed during breezy, near-neutral conditions at the Boulder Atmospheric Observatory tower to quantify the effects of an abrupt 20- to 30-m increase in terrain located 3–5 km west of the tower. Results indicate ...

Brent M. Bowen

2000-05-01T23:59:59.000Z

235

Section 1: Interfacial Turbulence and AirWater Scalar Transfer Turbulence and wave dynamics across gasliquid interfaces 1  

E-Print Network (OSTI)

The calculation of the gas transfer between the ocean and atmosphere13 S.A. Kitaigorodskii The influence of wind relationship to airwater gas transfer rates51 D. Turney, S. Banerjee Turbulent gas flux measurements near the airwater interface in an oscillating-grid tank 65 J.G. Janzen, H.E. Schulz, G.H. Jirka Sensible and latent

Takada, Shoji

236

Fossil turbulence and fossil turbulence waves can be dangerous  

E-Print Network (OSTI)

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.

Carl H Gibson

2012-11-25T23:59:59.000Z

237

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

Science Conference Proceedings (OSTI)

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.

Not Available

2012-10-01T23:59:59.000Z

238

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

Science Conference Proceedings (OSTI)

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.

Not Available

2012-11-01T23:59:59.000Z

239

ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS  

Science Conference Proceedings (OSTI)

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.

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)

2012-08-20T23:59:59.000Z

240

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

DOE Green Energy (OSTI)

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.

Rodney Frehlich

2012-10-30T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Passively cooled direct drive wind turbine  

SciTech Connect

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.

Costin, Daniel P. (Chelsea, VT)

2008-03-18T23:59:59.000Z

242

Improvement Of The Wind Farm Model Flap For Offshore Applications  

E-Print Network (OSTI)

The wind farm program FLaP (Farm Layout Program), developed at the University of Oldenburg, has been extended to improve the description of wake development in offshore conditions, especially the low ambient turbulence and the effect of atmospheric stability. Model results have been compared with measurements from the Danish offshore wind farm Vindeby. Vertical wake profiles and mean turbulence intensities in the wake were compared for 32 scenarios of single, double and quintuple wake cases with different mean wind speed, turbulence intensity and atmospheric stability. It was found that within the measurement uncertainties the results of the wake model compares well with the measurements for the most important ambient conditions. The effect of the low turbulence intensity offshore on the wake development was modelled well. Deviations have been found when atmospheric stability deviates from near-neutral conditions. Especially for stable atmospheric conditions both the free flow model and the wake model do not give satisfying results.

Bernhard Lange; Hans-peter Waldl; Rebecca Barthelmie; Algert Gil Guerrero; Detlev Heinemann

2002-01-01T23:59:59.000Z

243

IMPROVEMENT OF THE WIND FARM MODEL FLAP FOR OFFSHORE APPLICATIONS Bernhard Lange(1), Hans-Peter Waldl(1)(2), Rebecca Barthelmie(3), Algert Gil Guerrero(1)(4), Detlev Heinemann(1)  

E-Print Network (OSTI)

Vindeby. Vertical wake profiles and mean turbulence intensities in the wake were compared for 32 scenarios. Additionally, an estimation of turbulence intensity in the wind farm is essential for the load assumptions used in the description of the ambient vertical wind speed profile, but most importantly it leads to a low and wind speed

244

Chemical turbulence equivalent to Nikolavskii turbulence  

E-Print Network (OSTI)

We find evidence that a certain class of reaction-diffusion systems can exhibit chemical turbulence equivalent to Nikolaevskii turbulence. The distinctive characteristic of this type of turbulence is that it results from the interaction of weakly stable long-wavelength modes and unstable short-wavelength modes. We indirectly study this class of reaction-diffusion systems by considering an extended complex Ginzburg-Landau (CGL) equation that was previously derived from this class of reaction-diffusion systems. First, we show numerically that the power spectrum of this CGL equation in a particular regime is qualitatively quite similar to that of the Nikolaevskii equation. Then, we demonstrate that the Nikolaevskii equation can in fact be obtained from this CGL equation through a phase reduction procedure applied in the neighborhood of a codimension-two Turing--Benjamin-Feir point.

Dan Tanaka

2004-03-09T23:59:59.000Z

245

Wind Easements | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Wind Easements Wind Easements Wind Easements < Back Eligibility Agricultural Fed. Government Institutional Local Government Nonprofit Residential Schools State Government Tribal Government Savings Category Wind Buying & Making Electricity Program Info State South Dakota Program Type Solar/Wind Access Policy Provider S.D. Energy Management Office Any South Dakota property owner may grant a wind easement with the same effect as a conveyance of an interest in real property. Easements must be established in writing, and must be filed, recorded and indexed in the office of the register of deeds of the county in which they are granted. The maximum term of an easement is 50 years. Any payments associated with an easement must be made on an annual basis to the owner of the real property. An easement must include the following information:

246

Wind Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

FUPWG Meeting FUPWG Meeting NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC Robi Robichaud November 18, 2009 Topics Introduction Review of the Current Wind Market Drivers for Wind Development Siting g Issues Wind Resource Assessment Wind Characteristics Wind Power Potential Basic Wind Turbine Theory Basic Wind Turbine Theory Types of Wind Turbines Facts About Wind Siting Facts About Wind Siting Wind Performance 1. United States: MW 1 9 8 2 1 9 8 3 1 9 8 4 1 9 8 5 1 9 8 6 1 9 8 7 1 9 8 8 1 9 8 9 1 9 9 0 1 9 9 1 1 9 9 2 1 9 9 3 1 9 9 4 1 9 9 5 1 9 9 6 1 9 9 7 1 9 9 8 1 9 9 9 2 0 0 0 2 0 0 1 2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6 2 0 0 7 2 0 0 8 Current Status of the Wind Industry Total Global Installed Wind Capacity Total Global Installed Wind Capacity Total Global Installed Wind Capacity

247

Haxtun Wind Project | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Haxtun Wind Project Haxtun Wind Project Haxtun Wind Project November 13, 2013 - 10:45am Addthis The Haxtun Wind project in Phillips County, Colorado, is a community-owned 30 megawatt wind farm. The U.S. Department of Energy provided more than $2.5 million in funding for this Community Renewable Energy Deployment (CommRE) project. Wind Farm Phillips County is located in northeastern Colorado. The Haxtun Wind CommRE project will consist of up to 20 turbines located on more than 9,200 acres just south of the town of Haxtun, Colorado, and will tie into the grid at the existing Haxtun substation with few additional improvements needed. To ensure success, the Haxtun Wind project needs to be located on a site with a good wind resource, accessible transmission, a supportive community,

248

NREL: Wind Research - Computer-Aided Engineering Tools  

NLE Websites -- All DOE Office Websites (Extended Search)

Computer-Aided Engineering Tools Computer-Aided Engineering Tools Illustration of an offshore wind turbine on a barge with an illustration of how the moorings would work. A simulation of a 5-MW wind turbine on an offshore semi-submersible with catenary moorings. The National Wind Technology Center (NWTC) at NREL develops advanced computer-aided engineering (CAE) tools to support the wind and water power industries with state-of-the-art design and analysis capabilities. We have developed many software tools that produce realistic models that simulate the behavior of wind and water power technologies in complex environments-storm winds, waves offshore, earthquake loading, and extreme turbulence-and model the effects of turbulent inflow, unsteady aerodynamic forces, structural dynamics, drivetrain response, control

249

Solar and Wind Rights | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and Wind Rights and Wind Rights Solar and Wind Rights < Back Eligibility Commercial Fed. Government General Public/Consumer Industrial Local Government Nonprofit Residential Schools State Government Savings Category Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Water Heating Wind Program Info State Wisconsin Program Type Solar/Wind Access Policy Provider Public Service Commission of Wisconsin Wisconsin has several laws that protect a resident's right to install and operate a solar or wind energy system. These laws cover zoning restrictions by local governments, private land use restrictions, and system owner rights to unobstructed access to resources. Wisconsin permitting rules and model policy for small wind can be found [http://dsireusa.org/incentives/incentive.cfm?Incentive_Code=WI16R&re=1&ee=1

250

INL Wind Farm Project Description Document  

DOE Green Energy (OSTI)

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.

Gary Siefert

2009-07-01T23:59:59.000Z

251

Four Lectures on Turbulent Combustion  

E-Print Network (OSTI)

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

Peters, Norbert

252

A Model of Strongly Forced Wind Waves  

Science Conference Proceedings (OSTI)

A model of surface waves generated on deep water by strong winds is proposed. A two-layer approximation is adopted, in which a shallow turbulent layer overlies the lower, infinitely deep layer. The dynamics of the upper layer, which is directly ...

Alexey V. Fedorov; W. Kendall Melville

2009-10-01T23:59:59.000Z

253

Utility-Scale Wind Turbines | Open Energy Information  

Open Energy Info (EERE)

and Economic Development. Accessed September 27, 2013. References "U.S. Department of Energy. 2012 Market Report on U.S. Wind Technologies in Distributed Applications"...

254

NREL-Philippine Wind Farm Analysis and Site Selection Analysis...  

Open Energy Info (EERE)

National Renewable Energy Laboratory Sector: Energy Focus Area: Renewable Energy, Wind Topics: Co-benefits assessment, - Energy Access, Low emission development planning,...

255

Density Spectrum in the Solar Wind Plasma  

E-Print Network (OSTI)

The density fluctuation spectrum in the solar wind reveals a Kolmogorov-like scaling with a spectral slope of -5/3 in wavenumber space. The energy transfer process in the magnetized solar wind, characterized typically by MHD turbulence, over extended length-scales remains an unresolved paradox of modern turbulence theories, raising the question of how a compressible magnetofluid exhibits a turbulent spectrum that is characteristic of an incompressible hydrodynamic fluid. To address these questions, we have undertaken three-dimensional time dependent numerical simulations of a compressible magnetohydrodynamic fluid describing super-Alfv\\'enic, supersonic and strongly magnetized plasma fluid. It is shown that a Kolmogorov-like density spectrum can develop by plasma motions that are dominated by Alfv\\'enic cascades whereas compressive modes are dissipated.

Shaikh, Dastgeer

2009-01-01T23:59:59.000Z

256

The first turbulent combustion  

E-Print Network (OSTI)

The first turbulent combustion arises in a hot big bang cosmological model Gibson (2004) where nonlinear exothermic turbulence permitted by quantum mechanics, general relativity, multidimensional superstring theory, and fluid mechanics cascades from Planck to strong force freeze out scales with gravity balancing turbulent inertial-vortex forces. Interactions between Planck scale spinning and non-spinning black holes produce high Reynolds number turbulence and temperature mixing with huge Reynolds stresses driving the rapid inflation of space. Kolmogorovian turbulent temperature patterns are fossilized as strong-force exponential inflation stretches them beyond the scale of causal connection ct where c is light speed and t is time. Fossil temperature turbulence patterns seed nucleosynthesis, and then hydro-gravitational structure formation in the plasma epoch, Gibson (1996, 2000). Evidence about formation mechanisms is preserved by cosmic microwave background temperature anisotropies. CMB spectra indicate hydro-gravitational fragmentation at supercluster to galaxy masses in the primordial plasma with space stretched by \\~10^50. Bershadskii and Sreenivasan (2002, 2003) CMB multi-scaling coefficients support a strong turbulence origin for the anisotropies prior to the plasma epoch.

Carl H. Gibson

2005-01-19T23:59:59.000Z

257

Session: Wind industry project development  

DOE Green Energy (OSTI)

This first session at the Wind Energy and Birds/Bats workshop consisted of two presentations followed by a question and answer period. The session was intended to provide a general overview of wind energy product development, from the industry's perspective. Tom Gray of AWEA presented a paper titled ''State of the Wind Energy Industry in 2004'', highlighting improved performance and lower cost, efforts to address avian impacts, a status of wind energy in comparison to other energy-producing sources, and ending on expectations for the near future. Sam Enfield of Atlantic Renewable Energy Corporation presented a paper titled ''Key Factors for Consideration in Wind Plant Siting'', highlighting factors that wind facility developers must consider when choosing a site to build wind turbines and associated structures. Factors covered include wind resources available, ownership and land use patterns, access to transmission lines, accessibility and environmental impacts. The question and answer sum mary included topics related to risk taking, research and development, regulatory requirements, and dealing with utilities.

Gray, Tom; Enfield, Sam

2004-09-01T23:59:59.000Z

258

SPECTRUM OF KINETIC-ALFVEN TURBULENCE  

Science Conference Proceedings (OSTI)

A numerical study of strong kinetic-Alfven turbulence at scales smaller than the ion gyroscale is presented, and a phenomenological model is proposed that argues that magnetic and density fluctuations are concentrated mostly in two-dimensional structures, which leads to their Fourier energy spectra E(k ){proportional_to}k {sup -8/3} , where k is the wavevector component normal to the strong background magnetic field. The results may provide an explanation for recent observations of magnetic and density fluctuations in the solar wind at sub-proton scales.

Boldyrev, Stanislav; Perez, Jean Carlos [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)

2012-10-20T23:59:59.000Z

259

NREL-International Wind Resource Maps | Open Energy Information  

Open Energy Info (EERE)

International Wind Resource Maps International Wind Resource Maps Jump to: navigation, search Tool Summary Name: NREL-International Wind Resource Maps Agency/Company /Organization: National Renewable Energy Laboratory Sector: Energy Focus Area: Wind Topics: Resource assessment Website: www.nrel.gov/wind/international_wind_resources.html NREL-International Wind Resource Maps Screenshot References: International Wind Resource Maps [1] Logo: NREL-International Wind Resource Maps This resource provides access to NREL-developed wind resource maps and atlases for several countries. NREL's wind mapping projects have been supported by the U.S. Department of Energy, U.S. Agency for International Development, and United Nations International Programme. "NREL is helping to develop high-resolution projections of wind resources

260

Wind loading on solar collectors  

DOE Green Energy (OSTI)

The present design methodology for the determination of wind loading on the various solar collectors has been reviewed and assessed. The total force coefficients of flat plates of aspect ratios 1.0 and 3.0, respectively, at various angles of attack obtained by using the guidelines of the ANSI A58.1-1982, have been compared with those obtained by using the methodology of the ASCE Task Committee, 1961, and the experimental results of the full-scale test of heliostats by Peglow. The turbulent energy spectra, currently employed in the building code, are compared with those of Kaimal et al., Lumley, and Ponofsky for wind velocities of 20.0 m/s and 40.24 m/s at an elevation of 9.15 m. The longitudinal spectra of the building code overestimates the Kaimal spectra in the frequency range of 0.007 Hz to 0.08 Hz and underestimates beyond the frequency of 0.08 Hz. The peak angles of attack, on the heliostat, stowed in horizontal position, due to turbulent vertical and lateral components of wind velocity, have been estimated by using Daniel's methodology for three wind velocities and compared with the value suggested by the code. The experimental results of a simple test in the laboratory indicate the feasibility of decreasing the drag forces of the flat plate by reducing the solidity ratio.

Bhaduri, S.; Murphy, L.M.

1985-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Observations of Edge Turbulence  

NLE Websites -- All DOE Office Websites (Extended Search)

Edge Turbulence 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 Center *Princeton Plasma Physics Laboratory + MPI for Plasma Physics, EURATOM Assoc., Greifswald, Germany American Physical Society - Div. of Plasma Physics Orlando, FL Nov. 12 - Nov. 16, 2007 APS-2007 (2) Background and Motivation for "Xpt-region" View Strong edge turbulence has been observed in nearly all magnetic confinement devices. Desire predictive capability Most previous measurements made near outboard midplane where the turbulence has the following main features: - generation is ballooning-like (absent at inboard midplane, etc.) - filaments/blobs moves radially outward with some poloidal motion

262

ARM - Measurement - Atmospheric turbulence  

NLE Websites -- All DOE Office Websites (Extended Search)

turbulence turbulence ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Atmospheric turbulence High frequency velocity fluctuations that lead to turbulent transport of momentum, heat, mositure, and passive scalars, and often expressed in terms of variances and covariances. Categories Atmospheric State, Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System

263

EIA: Wind  

U.S. Energy Information Administration (EIA)

Technical information and data on the wind energy industry from the U.S. Energy Information Administration (EIA).

264

MHD Turbulence Revisited  

E-Print Network (OSTI)

Kraichnan (1965) proposed that MHD turbulence occurs as a result of collisions between oppositely directed Alfv\\'en wave packets. Recent work has generated some controversy over the nature of non linear couplings between colliding Alfv\\'en waves. We find that the resolution to much of the confusion lies in the existence of a new type of turbulence, intermediate turbulence, in which the cascade of energy in the inertial range exhibits properties intermediate between those of weak and strong turbulent cascades. Some properties of intermediate MHD turbulence are: (i) in common with weak turbulent cascades, wave packets belonging to the inertial range are long lived; (ii) however, components of the strain tensor are so large that, similar to the situation in strong turbulence, perturbation theory is not applicable; (iii) the breakdown of perturbation theory results from the divergence of neighboring field lines due to wave packets whose perturbations in velocity and magnetic fields are localized, but whose perturbations in displacement are not; (iv) 3--wave interactions dominate individual collisions between wave packets, but interactions of all orders $n\\geq 3$ make comparable contributions to the intermediate turbulent energy cascade; (v) successive collisions are correlated since wave packets are distorted as they follow diverging field lines; (vi) in common with the weak MHD cascade, there is no parallel cascade of energy, and the cascade to small perpendicular scales strengthens as it reaches higher wave numbers; (vii) For an appropriate weak excitation, there is a natural progression from a weak, through an intermediate, to a strong cascade.

P. Goldreich; S. Sridhar

1996-12-31T23:59:59.000Z

265

The Influence of Stratification and Nonlocal Turbulent Production on Estuarine Turbulence: An Assessment of Turbulence Closure with Field Observations  

Science Conference Proceedings (OSTI)

Field observations of turbulent kinetic energy (TKE), dissipation rate ?, and turbulent length scale demonstrate the impact of both density stratification and nonlocal turbulent production on turbulent momentum flux. The data were collected in a ...

Malcolm E. Scully; W. Rocky Geyer; John H. Trowbridge

2011-01-01T23:59:59.000Z

266

Dependence of Wind Turbine Curves on Atmospheric Stability Regimes - An Analysis of a West Coast North American Tall Wind Farm  

DOE Green Energy (OSTI)

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 in the boundary layer. Depending on whether the boundary layer is stable, convective or neutral, mean wind speed (U) and turbulence ({sigma}{sub U}) may vary greatly across the tall turbine swept area (40 m to 120 m). This variation can cause a single turbine to produce difference amounts of power during time periods of identical hub height wind speeds. The study examines the influence that atmospheric mixing or stability has on power output at a West Coast North American wind farm. They first examine the accuracy and applicability of two, relatively simple stability parameters, the wind shear-exponent, {alpha}, and the turbulence intensity, I{sub u}, against the physically-based, Obukhov length, L, to describe the wind speed and turbulence profiles in the rotor area. In general, the on-site stability parameters {alpha} and I{sub u} are in high agreement with the off-site, L stability scale parameter. Next, they divide the measurement period into five stability classes (strongly stable, stable, neutral, convective, and strongly convective) to discern stability-effects on power output. When only the mean wind speed profile is taken into account, the dependency of power output on boundary layer stability is only subtly apparent. When turbulence intensity I{sub u} is considered, the power generated for a given wind speed is twenty percent higher during strongly stable conditions than during strongly convective conditions as observed in the spring and summer seasons at this North American wind farm.

Wharton, S; Lundquist, J K; Sharp, J; Zulauf, M

2009-08-24T23:59:59.000Z

267

Wind Farm Recommendation Report  

Science Conference Proceedings (OSTI)

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.

John Reisenauer

2011-05-01T23:59:59.000Z

268

Wind Blog  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

wind-blog Office of Energy Efficiency & Renewable wind-blog Office of Energy Efficiency & Renewable Energy Forrestal Building 1000 Independence Avenue, SW Washington, DC 20585 en Two Facilities, One Goal: Advancing America's Wind Industry http://energy.gov/eere/articles/two-facilities-one-goal-advancing-america-s-wind-industry wind-industry" class="title-link">Two Facilities, One Goal: Advancing America's Wind Industry

269

Self Consistent Models of the Solar Wind  

E-Print Network (OSTI)

The origins of the hot solar corona and the supersonically expanding solar wind are still the subject of much debate. This paper summarizes some of the essential ingredients of realistic and self-consistent models of solar wind acceleration. It also outlines the major issues in the recent debate over what physical processes dominate the mass, momentum, and energy balance in the accelerating wind. A key obstacle in the way of producing realistic simulations of the Sun-heliosphere system is the lack of a physically motivated way of specifying the coronal heating rate. Recent models that assume the energy comes from Alfven waves that are partially reflected, and then dissipated by magnetohydrodynamic turbulence, have been found to reproduce many of the observed features of the solar wind. This paper discusses results from these models, including detailed comparisons with measured plasma properties as a function of solar wind speed. Some suggestions are also given for future work that could answer the many remain...

Cranmer, Steven R

2010-01-01T23:59:59.000Z

270

Stakeholder Engagement and Outreach: About Wind Powering America  

Wind Powering America (EERE)

About About Printable Version Bookmark and Share Awards Contacts About the Stakeholder Engagement and Outreach Initiative This initiative is focused at advancing the appropriate deployment of wind energy systems while educating communities about the potential impacts of wind development, through supporting projects and activities: Delivering unbiased, relevant, and actionable information to policy and permitting processes, Expanding or preserving access to quality wind resources, Making decisions on wind deployment more certain and predictable for all stakeholders by reducing uncertainty around wind deployment related issues, Developing and providing tools to help communities understand the impact and benefits of potential wind development, and Supporting the development of a national wind workforce though the

271

Turbine Inflow Characterization at the National Wind Technology Center  

Science Conference Proceedings (OSTI)

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 show 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.

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

2012-01-01T23:59:59.000Z

272

Turbine Inflow Characterization at the National Wind Technology Center: Preprint  

DOE Green Energy (OSTI)

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.

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

2012-01-01T23:59:59.000Z

273

Fallacies of the Enthalpy Transfer Coefficient over the Ocean in High Winds  

Science Conference Proceedings (OSTI)

Mesoscale and large-scale atmospheric models use a bulk surface flux algorithm to compute the turbulent flux boundary conditions at the bottom of the atmosphere from modeled mean meteorological quantities such as wind speed, temperature, and ...

Edgar L Andreas

2011-07-01T23:59:59.000Z

274

A Phenomenological Model for Wind Speed and Shear Stress Profiles in Vegetation Cover Layers  

Science Conference Proceedings (OSTI)

A phenomenological model for the mean wind speed and Reynolds shear stress profiles with height in a vegetation cover layer is derived from forms suggested by truncation of the equations of turbulent fluid motion at second order in fluctuating ...

F. A. Albini

1981-11-01T23:59:59.000Z

275

Use of a Large Crane for Wind and Tracer Profiles in an Urban Setting  

Science Conference Proceedings (OSTI)

Although measured vertical profiles of wind, turbulence, and tracer concentrations are critical for understanding the urban boundary layer, it is problematic to field a sounding system or a tall structure to support anemometers in a densely ...

Frank J. Gouveia; Martin J. Leach; Joseph H. Shinn; William E. Ralph

2007-10-01T23:59:59.000Z

276

The Variational Assimilation Method for the Retrieval of Humidity Profiles with the Wind-Profiling Radar  

Science Conference Proceedings (OSTI)

Recently, a humidity estimation technique was developed by using the turbulence echo characteristics detected with a wind-profiling radar. This study is concerned with improvement of the retrieval algorithm for delineating a humidity profile from ...

Jun-ichi Furumoto; Shingo Imura; Toshitaka Tsuda; Hiromu Seko; Tadashi Tsuyuki; Kazuo Saito

2007-09-01T23:59:59.000Z

277

First- and Second-Order Closure Models for Wind in a Plant Canopy  

Science Conference Proceedings (OSTI)

Katul and Chang recently compared the performance of two second-order closure models with observations of wind and turbulence in the Duke Forest canopy, noting that such models “alleviate some of the theoretical objections to first-order closure.”...

J. D. Jean-Paul Pinard; John D. Wilson

2001-10-01T23:59:59.000Z

278

A Numerical Model Study of Nocturnal Drainage Flows with Strong Wind and Temperature Gradients  

Science Conference Proceedings (OSTI)

A second-moment turbulence-closure model described in Yamada and Bunker is used to simulate nocturnal drainage flows observed during the 1984 ASCOT field expedition in Brush Creek, Colorado. In order to simulate the observed strong wind ...

T. Yamada; S. Bunker

1989-07-01T23:59:59.000Z

279

E – ? model of spray-laden near-sea atmospheric layer in high wind conditions  

Science Conference Proceedings (OSTI)

In-depth understanding and accurate modelling of the interaction between ocean spray and a turbulent flow under high-wind conditions is essential for improving intensity forecasts of hurricanes and severe storms. Here we consider the E – ? closure ...

Yevgenii Rastigejev; Sergey A. Suslov

280

Enhancement of Crosswind Pollutant Dispersion by Steadily Veering Winds in Sea Breezes  

Science Conference Proceedings (OSTI)

An estimate is given of the relative importance of wind veering and turbulent diffusion in the mean horizontal spread of pollutant plumes in the atmosphere. Documented veering rates in sea breezes are used to illustrate the effect, and it is ...

D. G. Steyn; M. Segal

1990-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Uncertainty of Boundary Layer Heat Budgets Computed from Wind Profiler—RASS Networks  

Science Conference Proceedings (OSTI)

Uncertainties in the evaluation of the atmospheric heat budget, in which the turbulent heat flux divergence term is calculated as a residual, are investigated for a triangular array of 915-MHz wind profilers—radio acoustic sounding systems (RASS) ...

Markus Furger; C. David Whiteman; James M. Wilczak

1995-03-01T23:59:59.000Z

282

Effects of Wind Field Inhomogeneities on Doppler Beam Swinging Revealed by an Imaging Radar  

Science Conference Proceedings (OSTI)

In this work, the accuracy of the Doppler beam-swinging (DBS) technique for wind measurements is studied using an imaging radar—the turbulent eddy profiler (TEP) developed by the University of Massachusetts, with data collected in summer 2003. ...

B. L. Cheong; R. D. Palmer; T-Y. Yu; K-F. Yang; M. W. Hoffman; S. J. Frasier; F. J. Lopez-Dekker

2008-08-01T23:59:59.000Z

283

Wind Tunnel Aeroacoustic Tests of Six Airfoils for Use on Small Wind Turbines: Preprint  

DOE Green Energy (OSTI)

Aeroacoustic tests of seven airfoils were performed in an open jet anechoic wind tunnel. Six of the airfoils are candidates for use on small wind turbines operating at low Reynolds number. One airfoil was tested for comparison to benchmark data. Tests were conducted with and without boundary layer tripping. In some cases a turbulence grid was placed upstream in the test section to investigate inflow turbulence noise. An array of 48 microphones was used to locate noise sources and separate airfoil noise from extraneous tunnel noise. Trailing edge noise was dominant for all airfoils in clean tunnel flow. With the boundary layer untripped, several airfoils exhibited pure tones that disappeared after proper tripping was applied. In the presence of inflow turbulence, leading edge noise was dominant for all airfoils.

Migliore, P.; Oerlemans, S.

2003-12-01T23:59:59.000Z

284

Standards for Municipal Small Wind Regulations and Small Wind...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Standards for Municipal Small Wind Regulations and Small Wind Model Wind Ordinance Standards for Municipal Small Wind Regulations and Small Wind Model Wind Ordinance Eligibility...

285

Energy Basics: Wind Turbines  

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

Energy Basics Renewable Energy Printable Version Share this resource Biomass Geothermal Hydrogen Hydropower Ocean Solar Wind Wind Turbines Wind Resources Wind Turbines...

286

A Theory of Baroclinic Turbulence  

Science Conference Proceedings (OSTI)

Understanding the physical mechanism maintaining fluid turbulence remains a fundamental theoretical problem. The two-layer model is an analytically and computationally simple system in which the dynamics of turbulence can be conveniently studied; ...

Brian F. Farrell; Petros J. Ioannou

2009-08-01T23:59:59.000Z

287

Statistical Predictability of Decaying Turbulence  

Science Conference Proceedings (OSTI)

We use statistical models of turbulence with “eddy damping” (EDQNM) in order to study the problem of predictability of freely evolving two- and three-dimensional isotropic turbulent flows.

Olivier Métais; Marcel Lesieur

1986-05-01T23:59:59.000Z

288

Supersaturation Intermittency in Turbulent Clouds  

Science Conference Proceedings (OSTI)

It is hypothesized that bursts of high supersaturation are produced in turbulent, convective clouds through interactions between cloud droplets and the small-scale structure of atmospheric turbulence. This hypothesis is based on the observation ...

Raymond A. Shaw

2000-10-01T23:59:59.000Z

289

The Decay of Convective Turbulence  

Science Conference Proceedings (OSTI)

Using simulations with a large-eddy model we have studied the decay of convective turbulence in the atmospheric boundary layer when the upward surface sensible heat flux is suddenly stopped. The decay of turbulent kinetic energy and temperature ...

F. T. M. Nieuwstadt; R. A. Brost

1986-03-01T23:59:59.000Z

290

Risø–I–1206(EN) Wind Power Meteorology  

E-Print Network (OSTI)

Abstract Wind power meteorology has evolved as an applied science, firmly founded on boundary-layer meteorology, but with strong links to climatology and geography. It concerns itself with three main areas: siting of wind turbines, regional wind resource assessment, and short-term prediction of the wind resource. The history, status and perspectives of wind power meteorology are presented, with emphasis on physical considerations and on its practical application. Following a global view of the wind resource, the elements of boundary layer meteorology which are most important for wind energy are reviewed: wind profiles and shear, turbulence and gust, and extreme winds. The data used in wind power meteorology stem mainly from three sources: onsite wind measurements, the synoptic networks, and the re-analysis projects. Wind climate analysis, wind resource estimation and siting further require a detailed description of the topography of the terrain – with respect to the roughness of the surface, near-by obstacles, and orographical features. Finally, the meteorological models used for estimation and prediction of the wind are described; their classification,

Erik L. Petersen; Niels G. Mortensen; Lars L; Jørgen Højstrup; Helmut P. Frank

1997-01-01T23:59:59.000Z

291

Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD  

DOE Green Energy (OSTI)

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.

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

1997-09-01T23:59:59.000Z

292

NREL: Wind Research - Large Wind Turbine Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Research Search More Search Options Site Map Printable Version Large Wind Turbine Research NREL's utility scale wind system research addresses performance and...

293

Wind Turbines  

Energy.gov (U.S. Department of Energy (DOE))

Although all wind turbines operate on similar principles, several varieties are in use today. These include horizontal axis turbines and vertical axis turbines.

294

Access to the ALS  

NLE Websites -- All DOE Office Websites (Extended Search)

Access to the ALS Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to...

295

Access to the ALS  

NLE Websites -- All DOE Office Websites (Extended Search)

Gate Access Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to register...

296

Beyond the Betz Theory - Blockage, Wake Mixing and Turbulence  

E-Print Network (OSTI)

Recent analytical models concerning the limiting efficiency of marine hydrokinetic (MHK) devices are reviewed with an emphasis on the significance of blockages (of local as well as global flow passages) and wake mixing. Also discussed is the efficiency of power generation from fully developed turbulent open channel flows. These issues are primarily concerned with the design/optimization of tidal turbine arrays; however, some of them are relevant to wind turbines as well.

Nishino, Takafumi

2013-01-01T23:59:59.000Z

297

Wind Energy Act (Maine) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Wind Energy Act (Maine) Wind Energy Act (Maine) Wind Energy Act (Maine) < Back Eligibility Developer Utility Agricultural Commercial Construction Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Savings Category Wind Buying & Making Electricity Program Info State Maine Program Type Solar/Wind Access Policy Siting and Permitting The Maine Wind Energy Act is a summary of legislative findings that indicate the state's strong interest in promoting the development of wind energy and establish the state's desire to ease the regulatory process for

298

Origins of Aircraft-Damaging Clear-Air Turbulence during the 9 December 1992 Colorado Downslope Windstorm: Numerical Simulations and Comparison with Observations  

Science Conference Proceedings (OSTI)

Results from numerical simulations of the Colorado Front Range downslope windstorm of 9 December 1992 are presented. Although this case was not characterized by severe surface winds, the event caused extreme clear-air turbulence (CAT) aloft, as ...

Terry L. Clark; William D. Hall; Robert M. Kerr; Don Middleton; Larry Radke; F. Martin Ralph; Paul J. Neiman; David Levinson

2000-04-01T23:59:59.000Z

299

High-Resolution In Situ Profiling through the Stable Boundary Layer: Examination of the SBL Top in Terms of Minimum Shear, Maximum Stratification, and Turbulence Decrease  

Science Conference Proceedings (OSTI)

Some 50 separate high-resolution profiles of small-scale turbulence defined by the energy dissipation rate (?), horizontal wind speed, and temperature from near the surface, through the nighttime stable boundary layer (SBL), and well into the ...

B. B. Balsley; R. G. Frehlich; M. L. Jensen; Y. Meillier

2006-04-01T23:59:59.000Z

300

Wind Powering America: Wind Events  

Wind Powering America (EERE)

calendar.asp Lists upcoming wind calendar.asp Lists upcoming wind power-related events. en-us julie.jones@nrel.gov (Julie Jones) http://www.windpoweringamerica.gov/images/wpa_logo_sm.jpg Wind Powering America: Wind Events http://www.windpoweringamerica.gov/calendar.asp Pennsylvania Wind for Schools Educator Workshop https://www.regonline.com/builder/site/Default.aspx?EventID=1352684 http://www.windpoweringamerica.gov/filter_detail.asp?itemid=4068 Wed, 4 Dec 2013 00:00:00 MST 2014 Joint Action Workshop http://www.windpoweringamerica.gov/filter_detail.asp?itemid=3996 http://www.windpoweringamerica.gov/filter_detail.asp?itemid=3996 Mon, 21 Oct 2013 00:00:00 MST AWEA Wind Project Operations and Maintenance and Safety Seminar http://www.windpoweringamerica.gov/filter_detail.asp?itemid=4009 http://www.windpoweringamerica.gov/filter_detail.asp?itemid=4009 Mon, 21

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Extreme Winds and Wind Effects on Structures  

Science Conference Proceedings (OSTI)

Extreme Winds and Wind Effects on Structures. Description/Summary: The Building and Fire Research Laboratory has an ...

2010-10-04T23:59:59.000Z

302

Mesoscale and Large-Eddy Simulations for Wind Energy  

Science Conference Proceedings (OSTI)

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.

Marjanovic, N

2011-02-22T23:59:59.000Z

303

Wind Energy Leasing Handbook  

E-Print Network (OSTI)

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?....................................................................

Balasundaram, Balabhaskar "Baski"

304

offshore wind | OpenEI  

Open Energy Info (EERE)

wind wind Dataset Summary Description Global Wind Potential Supply Curves by Country, Class, and Depth (quantities in GW) Source National Renewable Energy Laboratory Date Released July 12th, 2012 (2 years ago) Date Updated July 12th, 2012 (2 years ago) Keywords offshore resource offshore wind renewable energy potential Data application/vnd.openxmlformats-officedocument.spreadsheetml.sheet icon offshore_resource_100_vs2.xlsx (xlsx, 41.7 KiB) Quality Metrics Level of Review Peer Reviewed Comment Temporal and Spatial Coverage Frequency Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access Average vote Your vote

305

New report assesses offshore wind technology challenges and potential risks and benefits.  

E-Print Network (OSTI)

of the offshore wind energy industry, Large-Scale Offshore Wind Power in the United States. It provides a broad resource. The United States possesses large and accessible offshore wind energy resources. The availability of offshore wind energy facilities would generate an estimated $200 billion in new economic activity

306

Wind Powering America: New England Wind Forum  

Wind Powering America (EERE)

About the New England Wind Forum About the New England Wind Forum New England Wind Energy Education Project Historic Wind Development in New England State Activities Projects in New England Building Wind Energy in New England Wind Resource Wind Power Technology Economics Markets Siting Policy Technical Challenges Issues Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share The New England Wind Forum was conceived in 2005 as a platform to provide a single, comprehensive and objective source of up-to-date, Web-based information on a broad array of wind-energy-related issues pertaining to New England. The New England Wind Forum provides information to wind energy stakeholders through Web site features, periodic newsletters, and outreach activities. The New England Wind Forum covers the most frequently discussed wind energy topics.

307

Chapter 14: Wind Turbine Control Systems  

DOE Green Energy (OSTI)

Wind turbines are complex, nonlinear, dynamic systems forced by gravity, stochastic wind disturbances, and gravitational, centrifugal, and gyroscopic loads. The aerodynamic behavior of wind turbines is nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated three-dimensional turbulent wind inflow field that drives fatigue loading. Wind turbine modeling is also complex and challenging. Accurate models must contain many degrees of freedom (DOF) to capture the most important dynamic effects. The rotation of the rotor adds complexity to the dynamics modeling. Designs of control algorithms for wind turbines must account for these complexities. Algorithms must capture the most important turbine dynamics without being too complex and unwieldy. Off-the-shelf commercial soft ware is seldom adequate for wind turbine dynamics modeling. Instead, specialized dynamic simulation codes are usually required to model all the important nonlinear effects. As illustrated in Figure 14-1, a wind turbine control system consists of sensors, actuators and a system that ties these elements together. A hardware or software system processes input signals from the sensors and generates output signals for actuators. The main goal of the controller is to modify the operating states of the turbine to maintain safe turbine operation, maximize power, mitigate damaging fatigue loads, and detect fault conditions. A supervisory control system starts and stops the machine, yaws the turbine when there is a significant yaw misalignment, detects fault conditions, and performs emergency shut-downs. Other parts of the controller are intended to maximize power and reduce loads during normal turbine operation.

Wright, A. D.

2009-01-01T23:59:59.000Z

308

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

SciTech Connect

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.

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

2008-06-01T23:59:59.000Z

309

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

DOE Green Energy (OSTI)

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.

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

2008-06-01T23:59:59.000Z

310

Dynamic stall on wind turbine blades  

DOE Green Energy (OSTI)

Dynamic loads must be predicted accurately in order to estimate the fatigue life of wind turbines operating in turbulent environments. Dynamic stall contributes to increased dynamic loads during normal operation of all types of horizontal-axis wind turbine (HAWTs). This report illustrates how dynamic stall varies throughout the blade span of a 10 m HAWT during yawed and unyawed operating conditions. Lift, drag, and pitching moment coefficients during dynamics stall are discussed. Resulting dynamic loads are presented, and the effects of dynamic stall on yaw loads are demonstrated using a yaw loads dynamic analysis (YAWDYN). 12 refs., 22 figs., 1 tab.

Butterfield, C.P.; Simms, D.; Scott, G. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Hansen, A.C. [Utah Univ., Salt Lake City, UT (United States)] [Utah Univ., Salt Lake City, UT (United States)

1991-12-01T23:59:59.000Z

311

Using time-frequency and wavelet analysis to assess turbulence/rotor interactions  

DOE Green Energy (OSTI)

Large loading events on wind turbine rotor blades are often associated with transient bursts of coherent turbulent energy in the turbine inflow. These coherent turbulent structures are identified as peaks in the three-dimensional, instantaneous, turbulent shearing stress field. Such organized inflow structures and the accompanying rotor aeroelastic responses typically have time scales of only a few seconds and therefore do not lend themselves for analysis by conventional Fourier spectral techniques. Time-frequency analysis (and wavelet analysis in particular) offers the ability to more closely study the spectral decomposition of short period events such as the interaction of coherent turbulence with a moving rotor blade. In this paper, the authors discuss the initial progress in the application of time-frequency analysis techniques to the decomposition and interpretation of turbulence/rotor interaction. The authors discuss the results of applying both the continuous and discrete wavelet transforms for their application. Several examples are given of the techniques applied to both observed turbulence and turbine responses and those generated using numerical simulations. They found that the presence of coherent turbulent structures, as revealed by the inflow Reynolds stress field, is a major contributor to large load excursions. These bursts of coherent turbulent energy induce a broadband aeroelastic response in the turbine rotor as it passes through them.

Kelley, N.D.; Osgood, R.M.; Bialasiewicz, J.T.; Jakubowski, A.

2000-01-05T23:59:59.000Z

312

TMCC WIND RESOURCE ASSESSMENT  

DOE Green Energy (OSTI)

North Dakota has an outstanding resource--providing more available wind for development than any other state. According to U.S. Department of Energy (DOE) studies, North Dakota alone has enough energy from good wind areas, those of wind power Class 4 and higher, to supply 36% of the 1990 electricity consumption of the entire lower 48 states. At present, no more than a handful of wind turbines in the 60- to 100-kilowatt (kW) range are operating in the state. The first two utility-scale turbines were installed in North Dakota as part of a green pricing program, one in early 2002 and the second in July 2002. Both turbines are 900-kW wind turbines. Two more wind turbines are scheduled for installation by another utility later in 2002. Several reasons are evident for the lack of wind development. One primary reason is that North Dakota has more lignite coal than any other state. A number of relatively new minemouth power plants are operating in the state, resulting in an abundance of low-cost electricity. In 1998, North Dakota generated approximately 8.2 million megawatt-hours (MWh) of electricity, largely from coal-fired plants. Sales to North Dakota consumers totaled only 4.5 million MWh. In addition, the average retail cost of electricity in North Dakota was 5.7 cents per kWh in 1998. As a result of this surplus and the relatively low retail cost of service, North Dakota is a net exporter of electricity, selling approximately 50% to 60% of the electricity produced in North Dakota to markets outside the state. Keeping in mind that new electrical generation will be considered an export commodity to be sold outside the state, the transmission grid that serves to export electricity from North Dakota is at or close to its ability to serve new capacity. The markets for these resources are outside the state, and transmission access to the markets is a necessary condition for any large project. At the present time, technical assessments of the transmission network indicate that the ability to add and carry wind capacity outside of the state is limited. Identifying markets, securing long-term contracts, and obtaining a transmission path to export the power are all major steps that must be taken to develop new projects in North Dakota.

Turtle Mountain Community College

2003-12-30T23:59:59.000Z

313

Aleutian Pribilof Islands Wind Energy Feasibility Study  

DOE Green Energy (OSTI)

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.

Bruce A. Wright

2012-03-27T23:59:59.000Z

314

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

Energy.gov (U.S. Department of Energy (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...

315

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

E-Print Network (OSTI)

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.

S. V. Bogovalov; F. A. Aharonian

2000-03-11T23:59:59.000Z

316

Wake Characteristics of the MOD-2 Wind Turbine at Medicine Bow, Wyoming  

SciTech Connect

The present paper summarizes results obtained from profile measurements of the MOD-2 wind turbine wake at Medicine Bow, Wyoming. Vertical profiles of wind speed, potential temperature, and turbulence at 3 and 7 rotor diameters downstream of the turbine, taken under near neutral or slightly stable atmospheric conditions, are presented.

Jacobs, E. W.; Kelley, N. D.; McKenna, H. E.; Birkenheuer, N. B.

1984-11-01T23:59:59.000Z

317

The Probability Distribution of Sea Surface Wind Speeds: Effects of Variable Surface Stratification and Boundary Layer Thickness  

Science Conference Proceedings (OSTI)

Air–sea exchanges of momentum, energy, and material substances of fundamental importance to the variability of the climate system are mediated by the character of the turbulence in the atmospheric and oceanic boundary layers. Sea surface winds ...

Adam Hugh Monahan

2010-10-01T23:59:59.000Z

318

Modeling Turbulent Flow  

National Nuclear Security Administration (NNSA)

Turbulent Turbulent Flow with Implicit LES L.G. Margolin 1 Proceedings of the Joint Russian-American Five Laboratory Conference on Computational Mathematics/Physics 19-23 June, 2005 Vienna, Austria 1 Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, len@lanl.gov 1 Abstract Implicit large eddy simulation (ILES) is a methodology for modeling high Reynolds' num- ber flows that combines computational efficiency and ease of implementation with predictive calculations and flexible application. Although ILES has been used for more than fifteen years, it is only recently that significant effort has gone into providing a physical rationale that speaks to its capabilities and its limitations. In this talk, we will present new theoret- ical results aimed toward building a justification and discuss some remaining gaps in our understanding and our practical

319

Solar, Wind, and Energy Efficiency Easements and Rights Laws | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solar, Wind, and Energy Efficiency Easements and Rights Laws Solar, Wind, and Energy Efficiency Easements and Rights Laws Solar, Wind, and Energy Efficiency Easements and Rights Laws < Back Eligibility Residential Savings Category Appliances & Electronics Commercial Lighting Lighting Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Water Heating Wind Program Info State Colorado Program Type Solar/Wind Access Policy Provider Colorado Energy Office Colorado's solar access laws, which date back to 1979, prohibit any residential covenants that restrict solar access. [http://www.leg.state.co.us/CLICS/CLICS2008A/csl.nsf/fsbillcont3/3F45E0C8... HB 1270] of 2008 extended the law to protect installations of wind turbines that meet the state's interconnection standards, and certain

320

Wind News  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

news Office of Energy Efficiency & Renewable news Office of Energy Efficiency & Renewable Energy Forrestal Building 1000 Independence Avenue, SW Washington, DC 20585 en New Report Shows Trend Toward Larger Offshore Wind Systems, with 11 Advanced Stage Projects Proposed in U.S. Waters http://energy.gov/eere/articles/new-report-shows-trend-toward-larger-offshore-wind-systems-11-advanced-stage-projects wind-systems-11-advanced-stage-projects" class="title-link">New Report Shows Trend Toward Larger Offshore Wind Systems, with 11 Advanced Stage Projects Proposed in U.S. Waters

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Wind Power  

NLE Websites -- All DOE Office Websites (Extended Search)

Power As the accompanying map of New Mexico shows, the best wind power generation potential near WIPP is along the Delaware Mountain ridge line of the southern Guadalupe Mountains,...

322

ACCESS Magazine Fall 2005  

E-Print Network (OSTI)

enough hydrogen to meet demand Natural gas Coal Wind Bio*optimistic hydrogen-demand scenarios, natural gas use would

Cervero, Robert; Koppelman, Frank S.; Lipman, Timothy; Ogden, Joan; Varaiya, Pravin

2005-01-01T23:59:59.000Z

323

Fast Turbulent Reconnection  

E-Print Network (OSTI)

Reconnection is the process by which magnetic fields in a conducting fluid change their topology. This process is essential for understanding a wide variety of astrophysical processes, including stellar and galactic dynamos and astrophysical turbulence. To account for solar flares, solar cycles and the structure of the galactic magnetic field reconnection must be fast, propagating with a speed close to the Alfven speed. We show that the presence of a random magnetic field component substantially enhances the reconnection rate and enables fast reconnection, i.e. reconnection that does not depend on fluid resistivity. The enhancement of the reconnection rate is achieved via a combination of two effects. First of all, only small segments of magnetic field lines are subject to direct Ohmic annihilation. Thus the fraction of magnetic energy that goes directly into fluid heating goes to zero as fluid resistivity vanishes. However, the most important enhancement comes from the fact that unlike the laminar fluid case where reconnection is constrained to proceed line by line, the presence of turbulence enables many magnetic field lines to enter the reconnection zone simultaneously. A significant fraction of magnetic energy goes into MHD turbulence and this enhances reconnection rates through an increase in the field stochasticity. In this way magnetic reconnection becomes fast when field stochasticity is accounted for. As a consequence solar and galactic dynamos are also fast, i.e. do not depend on fluid resistivity.

A. Lazarian; E. Vishniac

2000-02-03T23:59:59.000Z

324

Wind Powering America Podcasts (Postcards), Wind Powering America (WPA), Energy Efficiency & Renewable Energy (EERE)  

Wind Powering America (EERE)

Photo from iStock/ 6495435 Photo from iStock/ 6495435 Wind Powering America Podcasts 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 * Wind Energy Development Can Revitalize Rural America. Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 10% post consumer waste. DOE/GO-102012-3585 · April 2012 windpoweringamerica.gov/podcasts_agricultural.asp

325

Wind Project Permitting | Open Energy Information  

Open Energy Info (EERE)

Project Permitting Project Permitting Jump to: navigation, search Invenergy is the developer of the 129-MW Forward Wind Energy Center project near Fond du Lac, Wisconsin, that came online in 2008. Photo by Ruth Baranowski, NREL 16412 As with other energy facility permitting processes, the goal of the wind project permitting process is to reach decisions that are timely, minimize challenges, and ensure compliance with laws and regulations that provide for necessary environmental protection.[1] Resources National Wind Coordinating Committee. (2002). Permitting of Wind Energy Facilities. Accessed August 28, 2013. This handbook is written for individuals and groups involved in evaluating wind projects: decision-makers and agency staff at all levels of government, wind developers, interested parties and the public.

326

Access to the ALS  

NLE Websites -- All DOE Office Websites (Extended Search)

Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to register with the ALS...

327

Renormalized weak plasma turbulence theory  

SciTech Connect

A renormalized Vlasov turbulence theory, derived by neglecting a mode coupling term in the Direct Interaction Approximation, is discussed. The theory reduces correctly to weak turbulence theory; it predicts both diffusion and polarization effects of the turbulent medium on test particles, as well as the inverse effects of the test particles on the medium. A heuristic, physical algorithm is presented for constructing the equations. The theory of the renormalized dielectric function is reviewed.

Krommes, J.A.; Kleva, R.G.

1979-02-01T23:59:59.000Z

328

Landowners and Wind Energy Development | Open Energy Information  

Open Energy Info (EERE)

Landowners and Wind Energy Development Landowners and Wind Energy Development Jump to: navigation, search Photo from Cielo Wind Power Corporation, NREL 10558 Many people will benefit from the clean air and economic growth brought about by wind power development, but farmers and other rural landowners may benefit the most. The best wind resources tend to be located in rural areas and on farmland in the Great Plains states. Wind power can provide a new cash crop for farmers and ranchers. Large wind turbines use only about one quarter-acre of land, including access roads, so farmers can continue to plant crops and graze livestock right up to the base of the turbines. One of the easiest and most attractive ways for farmers and other landowners to benefit from wind power is to allow wind developers to

329

Wind Energy Economic Development and Impacts | Open Energy Information  

Open Energy Info (EERE)

Wind Energy Economic Development and Impacts Wind Energy Economic Development and Impacts Jump to: navigation, search Wind turbine blades wind their way by train through Denver. Photo by Dennis Schroeder, NREL 20894 Meeting 20% of the nation's electricity demand with wind energy will lead to benefits to rural landowners and towns, the manufacturing sector, and infrastructure across America.[1] The following provide more information about wind energy and economic development: Resources European Wind Energy Association. Economic Benefits of Wind This page outlines the economic benefits of wind energy in Europe. National Renewable Energy Laboratory. (March 2013). Economic Development from New Generation and Transmission in Wyoming and Colorado. Accessed November 29, 2013. This fact sheet summarizes a recent analysis, commissioned by the Wyoming

330

Assessment of research needs for wind turbine rotor materials technology  

DOE Green Energy (OSTI)

Wind-driven power systems is a renewable energy technology that is still in the early stages of development. Wind power plants installed in early 1980s suffered structural failures chiefly because of incomplete understanding of wind forces (turbulent), in some cases because of poor product quality. Failures of rotor blades are now somewhat better understood. This committee has examined the experience base accumulated by wind turbines and the R and D programs sponsored by DOE. It is concluded that a wind energy system such as is described is within the capability of engineering practice; however because of certain gaps in knowledge, and the presence of only one major integrated manufacturer of wind power machines in the USA, a DOE R and D investment is still required.

Not Available

1991-01-01T23:59:59.000Z

331

Filtering Turbulent Sparsely Observed Geophysical Flows  

Science Conference Proceedings (OSTI)

Filtering sparsely turbulent signals from nature is a central problem of contemporary data assimilation. Here, sparsely observed turbulent signals from nature are generated by solutions of two-layer quasigeostrophic models with turbulent cascades ...

John Harlim; Andrew J. Majda

2010-04-01T23:59:59.000Z

332

Measurements of Enhanced Turbulent Mixing near Highways  

Science Conference Proceedings (OSTI)

In August and September of 2010, measurements of turbulent fluxes and turbulent kinetic energy were made on highways in the Toronto area (Ontario, Canada). In situ turbulence measurements were made with a mobile laboratory while driving on the ...

Mark Gordon; Ralf M. Staebler; John Liggio; Paul Makar; Shao-Meng Li; Jeremy Wentzell; Gang Lu; Patrick Lee; Jeffrey R. Brook

2012-09-01T23:59:59.000Z

333

Simulation of turbulence in fireballs  

SciTech Connect

The ALE technique is applied to the calculation of a small yield, low altitude nuclear explosion. When artificial diffusion effects caused by numerical errors are minimized, the fireball rises too rapidly, reaching an altitude in excess of that which is observed. This suggests that turbulent diffusion and entrainmert may be important. Hence, a turbulence model has been added to later calculations of the fireball dynamics. Some of the more important features of the calculational technique and the turbulence model are discussed. Preliminary results for a set of turbulence parameters and a particular low altitude fireball are presented. (auth)

Ruppel, H.M.; Gentry, R.A.; Daly, B.J.

1973-11-01T23:59:59.000Z

334

Model for simulating rotational data for wind turbine applications  

DOE Green Energy (OSTI)

This document describes a wind simulation model to be used in relation to wind turbine operations. The model is a computer code written in FORTRAN 77. The model simulates turbulence and mean wind effects as they are experienced at a rotating point on the blade of either a horizontal-axis wind turbine (HAWT) or a vertical-axis wind turbine (VAWT). The model is fast, requiring 15 to 120 seconds of VAX execution time to produce a simulation and related statistics. The model allows the user to set a number of wind parameters so that he may evaluate the uncertainty of model results as well as their typical values. When this capability is combined with short execution time, the user can quickly produce a number of simulations based on reasonable variation of input parameters and can use these simulations to obtain a range of wind turbine responses to the turbulence. This ability is important because some of the wind parameters that cannot be precisely evaluated should be prescribed over a range of values. This document is essentially a user's guide. Its features include theoretical derivations, samples of output, comparisons of measured and modeled results, a listing of the FORTRAN code, a glossary for the code, and the input and output of a sample run.

Powell, D.C.; Connell, J.R.

1986-04-01T23:59:59.000Z

335

Modeling the Long-Term Market Penetration of Wind in the United States  

DOE Green Energy (OSTI)

This paper presents an overview of the Wind Deployment Systems Model (WinDS). WinDS is a multiregional, multitime-period, Geographic Information System (GIS), and linear programming model of capacity expansion in the electric sector of the United States. WinDS is designed to address the principal market issues related to the penetration of wind energy technologies into the electric sector. These principal market issues include access to and cost of transmission, and the intermittency of wind power. WinDS addresses these issues through a highly discretized regional structure, explicit accounting for the variability in wind output over time, and consideration of ancillary services requirements and costs.

Short, W.; Blair, N.; Heimiller, D.; Singh, V.

2003-07-01T23:59:59.000Z

336

Capital Access Program (Vermont)  

Energy.gov (U.S. Department of Energy (DOE))

The Capital Access Program provides loan guarantees to small businesses seeking access to commercial credit. Premiums paid by the borrower and matched by Vermont Economic Development Authority fund...

337

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

DOE Green Energy (OSTI)

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.

Kelley, N. D.

2011-11-01T23:59:59.000Z

338

Space and Time Variations in Turbulence during the Manhattan Midtown 2005 Field Experiment  

Science Conference Proceedings (OSTI)

The Manhattan Midtown-2005 field experiment (MID05) collected turbulence observations at 12 street-level sites (at 3-m height) and at 5 rooftop sites (at 220-m average height). The MID05 observations of 30-min averaged standard deviations of wind ...

S. R. Hanna; Y. Zhou

2009-11-01T23:59:59.000Z

339

Measurements of Turbulence in the Upper-Ocean Mixing Layer Using Autosub  

Science Conference Proceedings (OSTI)

The rate of dissipation of turbulent kinetic energy has been measured with airfoil probes mounted on an autonomous vehicle, Autosub, on constant-depth legs at 2–10 m below the surface in winds up to 14 m s?1. The observations are mostly in an ...

S. A. Thorpe; T. R. Osborn; J. F. E. Jackson; A. J. Hall; R. G. Lueck

2003-01-01T23:59:59.000Z

340

The Coupling of Gravity Waves and Turbulence at White Sands, New Mexico, from VHF Radar Observations  

Science Conference Proceedings (OSTI)

Doppler spectra taken with the VHF Doppler radar at White Sands Missile Range are used to describe the winds and turbulence for 10 days in March?April 1991. The large power aperture product of this radar provides excellent data coverage in 150-m ...

G. D. Nastrom; F. D. Eaton

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

On the Use of Hot-Wire Anemometers for Turbulence Measurements in Clouds  

Science Conference Proceedings (OSTI)

The use of a hot-wire anemometer for high-resolution turbulence measurements in a two-phase flow (e.g., atmospheric clouds) is discussed. Experiments in a small wind tunnel (diameter of 0.2 and 2 m in length) with a mean flow velocity in the ...

Holger Siebert; Katrin Lehmann; Raymond A. Shaw

2007-06-01T23:59:59.000Z

342

Balancing of Wind Power.  

E-Print Network (OSTI)

?? In the future, renewable energy share, especially wind power share, in electricity generation is expected to increase. Due to nature of the wind, wind… (more)

Ülker, Muhammed Akif

2011-01-01T23:59:59.000Z

343

New England Wind Forum: Wind Power Technology  

Wind Powering America (EERE)

Wind Power Technology Wind Power Technology Modern wind turbines have become sophisticated power plants while the concept of converting wind energy to electrical energy remains quite simple. Follow these links to learn more about the science behind wind turbine technology. Wind Power Animation An image of a scene from the wind power animation. The animation shows how moving air rotates a wind turbine's blades and describes how the internal components work to produce electricity. It shows small and large wind turbines and the differences between how they are used, as stand alone or connected to the utility grid. How Wind Turbines Work Learn how wind turbines make electricity; what are the types, sizes, and applications of wind turbines; and see an illustration of the components inside a wind turbine.

344

NREL: Wind Research - Wind Resource Assessment  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Resource Assessment Wind Resource Assessment A map of the United States is color-coded to indicate the high winds at 80 meters. This map shows the wind resource at 80 meters for both land-based and offshore wind resources in the United States. Correct estimation of the energy available in the wind can make or break the economics of wind plant development. Wind mapping and validation techniques developed at the National Wind Technology Center (NWTC) along with collaborations with U.S. companies have produced high-resolution maps of the United States that provide wind plant developers with accurate estimates of the wind resource potential. State Wind Maps International Wind Resource Maps Dynamic Maps, GIS Data, and Analysis Tools Due to the existence of special use airspace (SUA) (i.e., military airspace

345

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

DOE Green Energy (OSTI)

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.

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

2013-09-01T23:59:59.000Z

346

Wind-Stress Coefficients at Light Winds  

Science Conference Proceedings (OSTI)

The increase of the wind-stress coefficient with wind velocity was found to start with winds as light as 3 m s?1, below which, following the formula for aerodynamically smooth flows, the wind-stress coefficient decreases as the wind velocity ...

Jin Wu

1988-12-01T23:59:59.000Z

347

Coronal Heating versus Solar Wind Acceleration  

E-Print Network (OSTI)

Parker's initial insights from 1958 provided a key causal link between the heating of the solar corona and the acceleration of the solar wind. However, we still do not know what fraction of the solar wind's mass, momentum, and energy flux is driven by Parker-type gas pressure gradients, and what fraction is driven by, e.g., wave-particle interactions or turbulence. SOHO has been pivotal in bringing these ideas back to the forefront of coronal and solar wind research. This paper reviews our current understanding of coronal heating in the context of the acceleration of the fast and slow solar wind. For the fast solar wind, a recent model of Alfven wave generation, propagation, and non-WKB reflection is presented and compared with UVCS, SUMER, radio, and in-situ observations at the last solar minimum. The derived fractions of energy and momentum addition from thermal and nonthermal processes are found to be consistent with various sets of observational data. For the more chaotic slow solar wind, the relative roles of steady streamer-edge flows (as emphasized by UVCS abundance analysis) versus bright blob structures (seen by LASCO) need to be understood before the relation between streamer heating and and slow-wind acceleration can be known with certainty. Finally, this presentation summarizes the need for next-generation remote-sensing observations that can supply the tight constraints needed to unambiguously characterize the dominant physics.

Steven R. Cranmer

2004-09-29T23:59:59.000Z

348

An investigation of wind loads on solar collectors. Appendix II - net pressure coefficients. Final report  

SciTech Connect

A wind-tunnel study of a series of model solar-collector installations (flat-plate collectors) immersed in a thick turbulent shear layer was undertaken in order to determine design wind loads on such installations. Wind tunnel measurements were made of the mean and fluctuating pressures on a model of a single flat-plate collector which was a component of different multi-panel installations. The pressures were spatially integrated over the top and bottom of the single collector separately.

Tieleman, H.W.; Akins, R.E.; Sparks, P.R.

1980-01-01T23:59:59.000Z

349

Stabilized space---time computation of wind-turbine rotor aerodynamics  

Science Conference Proceedings (OSTI)

We show how we use the Deforming-Spatial-Domain/Stabilized Space---Time (DSD/SST) formulation for accurate 3D computation of the aerodynamics of a wind-turbine rotor. As the test case, we use the NREL 5MW offshore baseline wind-turbine rotor. This class ... Keywords: DSD/SST formulation, Rotating turbulent flow, Space---time variational multiscale method, Torque values, Wind-turbine aerodynamics

Kenji Takizawa; Bradley Henicke; Tayfun E. Tezduyar; Ming-Chen Hsu; Yuri Bazilevs

2011-09-01T23:59:59.000Z

350

Turbulent Combustion Properties of Premixed Syngases  

NLE Websites -- All DOE Office Websites (Extended Search)

Turbulent Combustion Properties of Premixed Syngases Title Turbulent Combustion Properties of Premixed Syngases Publication Type Journal Article Year of Publication 2009 Authors...

351

Simulation of lean premixed turbulent combustion  

E-Print Network (OSTI)

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

2008-01-01T23:59:59.000Z

352

Advanced Computational Methods for Turbulence and Combustion...  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Computational Methods for Turbulence and Combustion Advanced Computational Methods for Turbulence and Combustion Bell.png Key Challenges: Development and application of...

353

Alfven Wave Collisions, The Fundamental Building Block of Plasma Turbulence IV: Laboratory Experiment  

E-Print Network (OSTI)

Turbulence is a phenomenon found throughout space and astrophysical plasmas. It plays an important role in solar coronal heating, acceleration of the solar wind, and heating of the interstellar medium. Turbulence in these regimes is dominated by Alfven waves. Most turbulence theories have been established using ideal plasma models, such as incompressible MHD. However, there has been no experimental evidence to support the use of such models for weakly to moderately collisional plasmas which are relevant to various space and astrophysical plasma environments. We present the first experiment to measure the nonlinear interaction between two counterpropagating Alfven waves, which is the building block for astrophysical turbulence theories. We present here four distinct tests that demonstrate conclusively that we have indeed measured the daughter Alfven wave generated nonlinearly by a collision between counterpropagating Alfven waves.

Drake, D J; Howes, G G; Kletzing, C A; Skiff, F; Carter, T A; Auerbach, D W

2013-01-01T23:59:59.000Z

354

ARM - PI Product - Cloud-Scale Vertical Velocity and Turbulent Dissipation  

NLE Websites -- All DOE Office Websites (Extended Search)

ProductsCloud-Scale Vertical Velocity and Turbulent ProductsCloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Site(s) NSA General Description 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

355

GROWTH OF A LOCALIZED SEED MAGNETIC FIELD IN A TURBULENT MEDIUM  

Science Conference Proceedings (OSTI)

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.

Cho, Jungyeon; Yoo, Hyunju, E-mail: jcho@cnu.ac.kr [Department of Astronomy and Space Science, Chungnam National University, Daejeon (Korea, Republic of)

2012-11-10T23:59:59.000Z

356

New England Wind Forum: Wind Power Economics  

Wind Powering America (EERE)

State Activities Projects in New England Building Wind Energy in New England Wind Resource Wind Power Technology Economics Cost Components Determining Factors Influencing Wind Economics in New England How does wind compare to the cost of other electricity options? Markets Siting Policy Technical Challenges Issues Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share Wind Power Economics Long-Term Cost Trends Since the first major installations of commercial-scale wind turbines in the 1980s, the cost of energy from wind power projects has decreased substantially due to larger turbine generators, towers, and rotor lengths; scale economies associated with larger projects; improvements in manufacturing efficiency, and technological advances in turbine generator and blade design. These technological advances have allowed for higher generating capacities per turbine and more efficient capture of wind, especially at lower wind speeds.

357

New England Wind Forum: Large Wind  

Wind Powering America (EERE)

Small Wind Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share Large Wind When establishing wind farms, wind energy developers generally approach landowners where they want to build. Interest in wind farms is frequently spurred by external pressures such as tax and other financial incentives and legislative mandates. Since each situation is influenced by local policies and permitting, we can only provide general guidance to help you learn about the process of installing wind turbines. Publications Wind Project Development Process Permitting of Wind Energy Facilities: A Handbook. (August 2002). National Wind Coordinating Collaborative. Landowner Frequently Asked Questions and Answers. (August 2003). "State Wind Working Group Handbook." pp. 130-133.

358

NREL: Wind Research - International Wind Resource Maps  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Resource Maps NREL is helping to develop high-resolution projections of wind resources worldwide. This allows for more accurate siting of wind turbines and has led to the...

359

NREL: Wind Research - Wind Project Development Updates  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Project Development Updates A 2.3 megawatt Siemens wind turbine nacelle on route to the Record Hill Wind project in Roxbury, Maine. January 14, 2013 As a result of the...

360

Wind Project Siting Tools | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Wind Project Siting Tools Jump to: navigation, search Photo from Alstom 2010, NREL 18207 The following tools are helpful for anyone planning a wind project. Resources Cadmus Group. (2012). Distributed Wind Site Analysis Tool. Accessed March 29, 2013. The Distributed Wind Site Analysis Tool is an online tool for conducting detailed site assessments for single-turbine projects, from residential to community scale. Eastern Interconnection States' Planning Council. (2013). EISPC EZ Mapping Tool. Accessed August 13, 2013. This free online mapping tool helps to identify potential clean energy

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

New England Wind Forum: Siting Considerations  

Wind Powering America (EERE)

Siting Considerations Siting Considerations Choosing a proper site for a wind turbine or farm is critical to a successful project. While the most important factors may vary from site to site, in any given instance a single factor can undermine success of an otherwise superlative project. On the other hand, sometimes a site may be weak in one area but so strong in another area that it is viable, such as a site with very strong winds that is farther than normal from a transmission line. A viable wind energy site generally includes the following key factors: Attractive Wind Resource Landowner and Community Support Feasible Permitting Compatible Land Use Nearby Access to an Appropriate Electrical Interconnect Point Appropriate Site Conditions for Access During Construction and Operations

362

Wind turbine  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

363

Magnetized Turbulent Dynamo in Protogalaxies  

Science Conference Proceedings (OSTI)

The prevailing theory for the origin of cosmic magnetic fields is that they have been amplified to their present values by the turbulent dynamo inductive action in the protogalactic and galactic medium. Up to now, in calculation of the turbulent dynamo, it has been customary to assume that there is no back reaction of the magnetic field on the turbulence, as long as the magnetic energy is less than the turbulent kinetic energy. This assumption leads to the kinematic dynamo theory. However, the applicability of this theory to protogalaxies is rather limited. The reason is that in protogalaxies the temperature is very high, and the viscosity is dominated by magnetized ions. As the magnetic field strength grows in time, the ion cyclotron time becomes shorter than the ion collision time, and the plasma becomes strongly magnetized. As a result, the ion viscosity becomes the Braginskii viscosity. Thus, in protogalaxies the back reaction sets in much earlier, at field strengths much lower than those which correspond to field-turbulence energy equipartition, and the turbulent dynamo becomes what we call the magnetized turbulent dynamo. In this paper we lay the theoretical groundwork for the magnetized turbulent dynamo. In particular, we predict that the magnetic energy growth rate in the magnetized dynamo theory is up to ten times larger than that in the kinematic dynamo theory. We also briefly discuss how the Braginskii viscosity can aid the development of the inverse cascade of magnetic energy after the energy equipartition is reached.

Leonid Malyshkin; Russell M. Kulsrud

2002-01-28T23:59:59.000Z

364

Advances in compressible turbulent mixing  

Science Conference Proceedings (OSTI)

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.

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

1992-01-01T23:59:59.000Z

365

An investigation of wind loads on solar collectors. Final report  

SciTech Connect

A wind-tunnel study of a series of model solar-collector installations (flat-plate collectors) immersed in a thick turbulent shear layer was undertaken in order to determine design wind loads on such installations. Wind tunnel measurements were made of the mean and fluctuating pressures on a model of a single flat-plate collector which was a component of different multi-panel installations. The pressures were spatially integrated over the top and bottom surface of the single collector separately.

Tieleman, H.W.; Akins, R.E.; Sparks, P.R.

1980-01-01T23:59:59.000Z

366

Turbulent molecular clouds  

E-Print Network (OSTI)

Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds trying to confront the two approaches wherever possible. After a broad presentation of the cold interstellar medium and molecular clouds, we emphasize the dynamical processes with special focus to turbulence and its impact on cloud evolution. We then review our knowledge of the velocity, density and magnetic fields. We end by openings towards new chemistry models and the links between molecular cloud structure and star--formation rates.

Hennebelle, Patrick

2012-01-01T23:59:59.000Z

367

Topic: Wind Engineering  

Science Conference Proceedings (OSTI)

Topic: Wind Engineering. Forty-Fourth Meeting of the UJNR Panel on Wind and Seismic Effects. NIST researchers collected ...

2011-08-31T23:59:59.000Z

368

Extreme Wind Speeds: Publications  

Science Conference Proceedings (OSTI)

... "Algorithms for Generating Large Sets of Synthetic Directional Wind Speed Data for Hurricane, Thunderstorm, and Synoptic Winds," NIST Technical ...

2013-08-19T23:59:59.000Z

369

NREL: Wind Research - Offshore Wind Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Options Site Map Printable Version Offshore Standards and Testing NREL's Offshore Wind Testing Capabilities 35 years of wind turbine testing experience Custom high speed data...

370

City of Santa Cruz - Solar Access Ordinance (California) | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Cruz - Solar Access Ordinance (California) Cruz - Solar Access Ordinance (California) City of Santa Cruz - Solar Access Ordinance (California) < Back Eligibility Commercial Construction Local Government Multi-Family Residential Residential Savings Category Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Swimming Pool Heaters Water Heating Wind Program Info State California Program Type Solar/Wind Access Policy Before a development plan can be approved in the City of Santa Cruz, it must be found that the orientation and location of buildings, structures, open spaces and other features of the site plan preserve solar access of adjacent properties. In addition, buildings and structures should be designed and oriented to make use of natural elements such as solar

371

Aerodynamic interference between two Darrieus wind turbines  

DOE Green Energy (OSTI)

The effect of aerodynamic interference on the performance of two curved bladed Darrieus-type vertical axis wind turbines has been calculated using a vortex/lifting line aerodynamic model. The turbines have a tower-to-tower separation distance of 1.5 turbine diameters, with the line of turbine centers varying with respect to the ambient wind direction. The effects of freestream turbulence were neglected. For the cases examined, the calculations showed that the downwind turbine power decrement (1) was significant only when the line of turbine centers was coincident with the ambient wind direction, (2) increased with increasing tipspeed ratio, and (3) is due more to induced flow angularities downstream than to speed deficits near the downstream turbine.

Schatzle, P.R.; Klimas, P.C.; Spahr, H.R.

1981-04-01T23:59:59.000Z

372

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

SciTech Connect

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.

Wiser, Ryan H; Hand, Maureen

2010-01-01T23:59:59.000Z

373

NREL: Wind Research - Small Wind Turbine Development  

NLE Websites -- All DOE Office Websites (Extended Search)

Small Wind Turbine Development Small Wind Turbine Development A photo of Southwest Windpower's Skystream wind turbine in front of a home. PIX14936 Southwest Windpower's Skystream wind turbine. A photo of the Endurance wind turbine. PIX15006 The Endurance wind turbine. A photo of the Atlantic Orient Corporation 15/50 wind turbine at the National Wind Technology Center. PIX07301 The Atlantic Orient Corporation 15/50 wind turbine at the National Wind Technology Center. NREL supports continued market expansion of small wind turbines by funding manufacturers through competitive solicitations (i.e., subcontracts and/or grants) to refine prototype systems leading to commercialization. Learn more about the turbine development projects below. Skystream NREL installed and tested an early prototype of this turbine at the

374

NREL: Wind Research - Small Wind Turbine Webinars  

NLE Websites -- All DOE Office Websites (Extended Search)

Small Wind Turbine Webinars Small Wind Turbine Webinars Here you will find webinars about small wind turbines that NREL hosted. Introducing WindLease(tm): Making Wind Energy Affordable NREL and the American Solar Energy Society (ASES) Wind Division co-hosted this webinar. (Text Version.) Date: August 1, 2013 Run Time: 40 minutes Joe Hess, VP of Business Development at United Wind, described United Wind's WindQuote and WindLease Program and explained the process from the dealer's and consumer's perspective. Texas Renewable Energy Industries Association NREL and the American Solar Energy Society (ASES) Wind Division co-hosted this webinar. (Text Version). Date: March 7, 2013 Run Time: 1 hour Russel Smith, Texas Renewable Energy Industries Association executive director and co-founder, provided an overview of the trade association

375

New England Wind Forum: Small Wind  

Wind Powering America (EERE)

Wind for Schools Project Funding Case Studies: Thomas Harrison Middle School, Virginia Wind for Schools Project Funding Case Studies: Thomas Harrison Middle School, Virginia August 26, 2013 Workshop Explores Information's Role in Wind Project Siting: A Wind Powering America Success Story November 19, 2012 More News Subscribe to News Updates Events Renewable Energy Market Update Webinar January 29, 2014 Strategic Energy Planning: Webinar February 26, 2014 Introduction to Wind Systems March 10, 2014 More Events Publications 2012 Market Report on Wind Technologies in Distributed Applications August 12, 2013 More Publications Features Sign up for the New England Wind Forum Newsletter. New England Wind Forum About the New England Wind Forum New England Wind Energy Education Project Historic Wind Development in New England State Activities Projects in New England

376

Stakeholder Engagement and Outreach: Wind for Schools Project  

Wind Powering America (EERE)

Participant Roles & Responsibilities Affiliate Projects Pilot Project Results Project Funding Collegiate Wind Competition School Project Locations Education & Training Programs Curricula & Teaching Materials Resources Wind for Schools Project As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. To address these issues, Wind Powering America launched the Wind for Schools project in 2005 by conducting a pilot project in Colorado that resulted in one small wind turbine installation in Walsenburg. The program has ended, but by the end of September 2013: Wind for Schools Portal on OpenEI Visit the OpenEI Wind for Schools Portal to access data from turbines at

377

Ring Ring. Who's There? A Wind Expert | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ring Ring. Who's There? A Wind Expert Ring Ring. Who's There? A Wind Expert Ring Ring. Who's There? A Wind Expert August 23, 2010 - 10:44am Addthis Stephen Graff Former Writer & editor for Energy Empowers, EERE Have a question about wind energy? You're not alone. In 2009, about 1,200 people- ranging from farmers, teachers, county commissioners, developers and green job hopefuls -called or emailed Minnesota-based Windustry's wind hotline to learn more about the renewable energy. "The questions are all over the map," said David Tidball, who has been fielding calls since early 2009. "It's everything from, 'What's a wind turbine look like?' to 'How do I get involved in a wind project of my own?'" Windustry's mission is to provide accurate, unbiased and accessible information to the public about wind energy and help people across the

378

On Collective Properties of Turbulent QED Plasma  

E-Print Network (OSTI)

Polarization properties of turbulent stochastically inhomogeneous ultrarelativistic QED plasma are studied. It is shown that the sign of nonlinear turbulent Landau damping corresponds to an instability of the spacelike modes and, for sufficiently large turbulent fields, to an actual instability of a system. Modification of plasmon dispersion relations due to turbulent effects are studied.

Martin Kirakosyan; Andrei Leonidov; Berndt Muller

2013-05-19T23:59:59.000Z

379

Description of the Columbia Basin Wind Energy Study (CBWES)  

SciTech Connect

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.

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

2012-10-01T23:59:59.000Z

380

Anemometer Data (Wind Speed, Direction) for Ugashik, AK (2001 - 2002) |  

Open Energy Info (EERE)

0 0 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142278290 Varnish cache server Anemometer Data (Wind Speed, Direction) for Ugashik, AK (2001 - 2002) Dataset Summary Description Wind data collected from Ugashik Traditional Village in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2001 through 2002, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp.

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Anemometer Data (Wind Speed, Direction) for Tanana, AK (2001 - 2002) |  

Open Energy Info (EERE)

40 40 Varnish cache server Anemometer Data (Wind Speed, Direction) for Tanana, AK (2001 - 2002) Dataset Summary Description Wind data collected from Tanana Village in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2001 through 2002, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago)

382

Web accessible image similarity measurements  

Science Conference Proceedings (OSTI)

Web accessible image similarity measurements. Background: There ... messages). Web Access to Image Similarity Measurements. ...

2013-04-16T23:59:59.000Z

383

Careers in the Wind Industry | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Careers in the Wind Industry Jump to: navigation, search Two engineers working in the nacelle of a Siemens offshore wind turbine. Photo from Siemens AG, NREL 19687 Resources American Wind Energy Association. Careers in Wind. Accessed August 29, 2013. This page connects wind energy companies to people seeking jobs in the wind energy industry. Environmental Entrepreneurs. (August 2013). Clean Energy Works for Us: 2013 Second Quarter Clean Energy/Clean Transportation Jobs Report. Accessed August 30, 2013 Environmental Entrepreneurs (e2) is a national community of business

384

Rotationally sampled wind characteristics for several rotor sizes using laser anemometer measurements  

DOE Green Energy (OSTI)

The concept of measuring the wind velocity rotationally around crosswind circles using a circle-scanning Doppler laser anemometer is investigated to determine the technique's suitability as an effective, simple, economical, and nonintrusive method for estimation turbulence at a wind turbine rotor. Estimates of wind features obtained using the lidar technique are compared to actual wind measurements obtained using a vertical plane array of anemometers, and to other estimates generated using a single-tower technique. Although the lack of a common data set precludes a firm conclusion regarding the lidar method's accuracy, it appears that the rotationally scanning lidar has the potential of becoming an excellent tool for measuring turbulent wind around the disk of rotation of a turbine blade. 11 refs., 21 figs., 2 tabs.

Connell, J.R.; Morris, V.R.

1989-02-01T23:59:59.000Z

385

City of Boulder - Solar Access Ordinance | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Access Ordinance Access Ordinance City of Boulder - Solar Access Ordinance < Back Eligibility Construction Residential Savings Category Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Water Heating Program Info State Colorado Program Type Solar/Wind Access Policy Provider City of Boulder The City of Boulder's solar access ordinance guarantees access, or "solar fences," to sunlight for homeowners and renters in the city. This is done by setting limits on the amount of permitted shading by new construction. A solar access permit is available to those who have installed or who plan to install a solar energy system and need more protection than is provided by the ordinance. For new developments, all units which are not planned to

386

Utility Wind Integration Group Distributed Wind/Solar Interconnection...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Utility Wind Integration Group Distributed WindSolar Interconnection Workshop Utility Wind Integration Group Distributed WindSolar Interconnection Workshop May 21, 2013 8:00AM...

387

The Wind Energy Outlook Scenarios 1 India Wind Energy  

E-Print Network (OSTI)

1 ?Status of wind energy in India ????????????????????6 Wind energy in India????????????????????????????????????????????????????????????????????????????????????7 Wind power resource assessment?????????????????????????????????????????????????????????6 Wind power installations by state?????????????????????????????????????????????????????????8

unknown authors

2012-01-01T23:59:59.000Z

388

Lidar Measurements of Wind in the Planetary Boundary Layer: The Method, Accuracy and Results from Joint Measurements with Radiosonde and Kytoon  

Science Conference Proceedings (OSTI)

During the Central Illinois Rainfall Chemistry Experiment (CIRCE), the University of Wisconsin lidar measured wind and turbulence profiles through the planetary boundary layer for a 32-h period in conjunction with surface observations, radiosonde ...

William P. Hooper; Edwin W. Eloranta

1986-07-01T23:59:59.000Z

389

NREL: Wind Research - Site Wind Resource Characteristics  

NLE Websites -- All DOE Office Websites (Extended Search)

Site Wind Resource Characteristics Site Wind Resource Characteristics A graphic showing the location of National Wind Technology Center and its wind power class 2. Click on the image to view a larger version. Enlarge image This graphic shows the wind power class at the National Wind Technology Center. You can download a printable copy. The National Wind Technology Center (NWTC) is on the Great Plains just miles from the Rocky Mountains. The site is flat and covered with short grasses. The terrain and lack of obstructions make the site highly suitable for testing wind turbines. Take a tour of the NWTC and its facilities to better understand its location and layout. Another prime feature of the NWTC is the strong directionality of the wind - most of the strong winds come within a few degrees of 285°. West of

390

NREL: Wind Research - Offshore Wind Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Offshore Wind Research Offshore Wind Research Photo of a European offshore wind farm. Early progress in European Offshore Wind Energy over the last decade provides a glimpse into the vast potential of the global offshore resource. For more than eight years, NREL has worked with the Department of Energy to become an international leader in offshore wind energy research. Capabilities NREL's offshore wind capabilities focus on critical areas that reflect the long-term needs of the offshore wind energy industry and the U.S. Department of Energy including: Offshore Design Tools and Methods Offshore Standards and Testing Energy Analysis of Offshore Systems Offshore Wind Resource Characterization Grid Integration of Offshore Wind Key Research NREL documented the status of offshore wind energy in the United States in

391

RESONANCE BROADENING AND HEATING OF CHARGED PARTICLES IN MAGNETOHYDRODYNAMIC TURBULENCE  

SciTech Connect

The heating, acceleration, and pitch-angle scattering of charged particles by magnetohydrodynamic (MHD) turbulence are important in a wide range of astrophysical environments, including the solar wind, accreting black holes, and galaxy clusters. We simulate the interaction of high-gyrofrequency test particles with fully dynamical simulations of subsonic MHD turbulence, focusing on the parameter regime with {beta} {approx} 1, where {beta} is the ratio of gas to magnetic pressure. We use the simulation results to calibrate analytical expressions for test particle velocity-space diffusion coefficients and provide simple fits that can be used in other work. The test particle velocity diffusion in our simulations is due to a combination of two processes: interactions between particles and magnetic compressions in the turbulence (as in linear transit-time damping; TTD) and what we refer to as Fermi Type-B (FTB) interactions, in which charged particles moving on field lines may be thought of as beads sliding along moving wires. We show that test particle heating rates are consistent with a TTD resonance that is broadened according to a decorrelation prescription that is Gaussian in time (but inconsistent with Lorentzian broadening due to an exponential decorrelation function, a prescription widely used in the literature). TTD dominates the heating for v{sub s} >> v{sub A} (e.g., electrons), where v{sub s} is the thermal speed of species s and v{sub A} is the Alfven speed, while FTB dominates for v{sub s} << v{sub A} (e.g., minor ions). Proton heating rates for {beta} {approx} 1 are comparable to the turbulent cascade rate. Finally, we show that velocity diffusion of collisionless, large gyrofrequency particles due to large-scale MHD turbulence does not produce a power-law distribution function.

Lynn, Jacob W. [Physics Department, University of California, Berkeley, CA 94720 (United States); Parrish, Ian J.; Quataert, Eliot [Astronomy Department and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States); Chandran, Benjamin D. G., E-mail: jacob.lynn@berkeley.edu [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)

2012-10-20T23:59:59.000Z

392

Simulation of doubly-fed machine with improved wind turbine  

Science Conference Proceedings (OSTI)

Most of wind turbines use induction generators that are very reliable with low costs [2], but when it is straightly connected to the grid, maximum power is not accessible [1] and only a few change of speed between maximum speed and synchronous speed ... Keywords: doubly-fed machine, gearbox ratio, high speed shaft, low speed shaft, wind turbine

Hengameh Kojooyan Jafari

2009-02-01T23:59:59.000Z

393

Freely propagating open premixed turbulent flames stabilized by swirl  

DOE Green Energy (OSTI)

A novel means has been developed for using weak swirl to stabilize freely propagating open premixed turbulent flames (swirl numbers between 0.05 to 0.3). By injecting a small amount of air tangentially into the co-flow of a concentric burner, stationary flames can be maintained above the burner exit for a large range of mixture, turbulence and flow conditions. The absence of physical surfaces in the vicinity of the flame provides free access to laser diagnostics. Laser Doppler anemometry and laser Mie scattering measurements of four flames with and without incident turbulence show that their features are typical of wrinkled laminar flames. The most distinct characteristics is that flame stabilization does not rely on flow recirculation. Centrifugal force induced by swirl causes flow divergence, and the flame is maintained at where the local mass flux balances the burning rate. The flame speeds can be estimated based on the centerline velocity vector, which is locally normal to the flame brush. This flame geometry is the closest approximation to the 1-D planar flame for determining fundamental properties to advance turbulent combustion theories. 18 refs.

Chan, C.K.; Lau, K.S.; Chin, W.K. (Hong Kong Polytechnic, Kowloon (Hong Kong)); Cheng, R.K. (Lawrence Berkeley Lab., CA (United States))

1991-12-01T23:59:59.000Z

394

Energy Basics: Wind Power Animation  

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

Energy Basics Renewable Energy Printable Version Share this resource Biomass Geothermal Hydrogen Hydropower Ocean Solar Wind Wind Turbines Wind Resources Wind Power...

395

Energy Basics: Wind Energy Resources  

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

Energy Basics Renewable Energy Printable Version Share this resource Biomass Geothermal Hydrogen Hydropower Ocean Solar Wind Wind Turbines Wind Resources Wind Energy...

396

Energy Basics: Wind Energy Technologies  

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

Energy Basics Renewable Energy Printable Version Share this resource Biomass Geothermal Hydrogen Hydropower Ocean Solar Wind Wind Turbines Wind Resources Wind Energy...

397

Energy Basics: Wind Energy Technologies  

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

Photo of a hilly field, with six visible wind turbines spinning in the wind. Wind energy technologies use the energy in wind for practical purposes such as generating...

398

Solar Wind | Open Energy Information  

Open Energy Info (EERE)

Wind Jump to: navigation, search Name Solar Wind Place Krasnodar, Romania Zip 350000 Sector Solar, Wind energy Product Russia-based PV product manufacturer. Solar Wind manufactures...

399

EERE: Wind Program Home Page  

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

wind projects and offshore wind resource potential. Offshore Wind R&D DOE makes strategic research & deployment investments to launch domestic offshore wind industry....

400

2011 Wind Technologies Market Report  

E-Print Network (OSTI)

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

Bolinger, Mark

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

2011 Wind Technologies Market Report  

E-Print Network (OSTI)

and K. Porter. 2011. Wind Power and Electricity Markets.41 6. Wind Power Priceat Various Levels of Wind Power Capacity Penetration Wind

Bolinger, Mark

2013-01-01T23:59:59.000Z

402

Horizon Wind  

E-Print Network (OSTI)

The Washington Department of Fish and Wildlife (WDFW) does not have regulatory authority specific to wind power development at this time. WDFW is an agency with environmental expertise as provided for through the Washington Administrative Code (WAC) 197-11-920. Comments related to environmental impacts are provided to regulatory authorities through the State Environmental Policy Act (SEPA) Revised Code of Washington (RCW) 43.21C review process.

Cover Photo; Nina Carter; Heath Packard; Lisa Paribello; Craig Dublanko; Dana Peck; Nicole Hughes; Bill Robinson; Robert Kruse; Arlo Corwin; Joe Buchanan; Ted Clausing; Eric Cummins; Travis Nelson; Eric Pentico; Mike Ritter; Jeff Tayer; James Watson; William Weiler; David Mcclure

2009-01-01T23:59:59.000Z

403

Finescale Parameterizations of Turbulent Dissipation  

Science Conference Proceedings (OSTI)

Fine- and microstructure data from a free fall profiler are analysed to test models that relate the turbulent dissipation rate (?) to characteristics of the internal wave field. The data were obtained from several distinct internal wave ...

Kurt L. Polzin; John M. Toole; Raymond W. Schmitt

1995-03-01T23:59:59.000Z

404

Predictability of Rotating Stratified Turbulence  

Science Conference Proceedings (OSTI)

Although predictability represents one of the fundamental problems in atmospheric science, gaps in our knowledge remain. Theoretical understanding of the inverse error cascade is limited mostly to homogeneous, isotropic turbulence, whereas ...

K. Ngan; P. Bartello; D. N. Straub

2009-05-01T23:59:59.000Z

405

NREL: Wind Research - Information and Outreach  

NLE Websites -- All DOE Office Websites (Extended Search)

small wind systems. Printable Version Wind Research Home Capabilities Projects Offshore Wind Research Large Wind Turbine Research Midsize Wind Turbine Research Small Wind Turbine...

406

Wind Vision Wind Farm | Open Energy Information  

Open Energy Info (EERE)

Wind Farm Wind Farm Jump to: navigation, search Name Wind Vision Wind Farm Facility Wind Vision Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Wind Vision Developer Wind Vision Location St. Ansgar IA Coordinates 43.348224°, -92.888816° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.348224,"lon":-92.888816,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

407

High Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

Winds Wind Farm Winds Wind Farm Jump to: navigation, search Name High Winds Wind Farm Facility High Winds Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner NextEra Energy Resources Developer NextEra Energy Resources Energy Purchaser PPM Energy Inc Location Solano County CA Coordinates 38.124844°, -121.764915° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":38.124844,"lon":-121.764915,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

408

NREL: Wind Research - Small Wind Turbine Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Small Wind Turbine Research Small Wind Turbine Research The National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Small Wind Project's objectives are to reduce barriers to wind energy expansion, stabilize the market, and expand the number of small wind turbine systems installed in the United States. "Small wind turbine" refers to a turbine smaller than or equal to 100 kilowatts (kW). "Distributed wind" includes small and midsize turbines (100 kW through 1 megawatt [MW]). Since 1996, NREL's small wind turbine research has provided turbine testing, turbine development, and prototype refinement leading to more commercially available small wind turbines. Work is conducted under the following areas. You can also learn more about state and federal policies

409

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

DOE Green Energy (OSTI)

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.

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

2012-01-01T23:59:59.000Z

410

Wind Energy Data and Information Gateway (WENDI) | Open Energy Information  

Open Energy Info (EERE)

Wind Energy Data and Information Gateway (WENDI) Wind Energy Data and Information Gateway (WENDI) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Wind Energy Data and Information Gateway (WENDI) Agency/Company /Organization: United States Department of Energy, Oak Ridge National Laboratory Sector: Energy Focus Area: Wind Topics: Market analysis, Resource assessment, Technology characterizations Resource Type: Dataset, Maps Website: windenergy.ornl.gov/ References: Wind Energy Data and Information Gateway (WENDI)[1] Logo: Wind Energy Data and Information Gateway (WENDI) The WENDI Gateway is an integrated system for the archival, discovery, access, integration, and delivery of wind energy-related data and information. NOTE The WENDI Gateway has been discontinued due to an absence of funding. Oak

411

Solar winds along curved magnetic field lines  

E-Print Network (OSTI)

Both remote-sensing measurements using the interplanetary scintillation (IPS) technique and in situ measurements by the Ulysses spacecraft show a bimodal structure for the solar wind at solar minimum conditions. At present what makes the fast wind fast and the slow wind slow still remains to be answered. While a robust empirical correlation exists between the coronal expansion rate $f_c$ of the flow tubes and the speeds $v$ measured in situ, further data analysis suggests that $v$ depends on more than just $f_c$. We examine whether the non-radial shape of field lines, which naturally accompanies any non-radial expansion, could be an additional geometrical factor. We solved the transport equations incorporating the heating due to turbulent Alfv\\'en waves for an electron-proton solar wind along curved field lines given by an analytical magnetic field model, representative of a solar minimum corona. The field line shape is found to influence substantially the solar wind parameters, reducing the asymptotic speed ...

Li, Bo; Chen, Yao

2011-01-01T23:59:59.000Z

412

Wind Power Today  

SciTech Connect

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.

2006-05-01T23:59:59.000Z

413

Wind Power Today  

DOE Green Energy (OSTI)

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.

Not Available

2007-05-01T23:59:59.000Z

414

Research Aircraft Observations of the Mean and Turbulent Structure of a Low-Level Jet Accompanying a Strong Storm  

Science Conference Proceedings (OSTI)

A NOAA P-3 research aircraft collected measurements in a storm off of the U.S. West Coast that featured a low-level jet with wind speeds approaching 50 m s?1. These measurements have been used to document mean and turbulent boundary layer ...

Nicholas A. Bond; Bernard A. Walter

2002-12-01T23:59:59.000Z

415

Anemometer Data (Wind Speed, Direction) for YKHC-Bethel, AK (2003 - 2004) |  

Open Energy Info (EERE)

YKHC-Bethel, AK (2003 - 2004) YKHC-Bethel, AK (2003 - 2004) Dataset Summary Description Wind data collected from YKHC - Bethel in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2003 through 2004, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago) Keywords wind wind direction wind speed

416

An examination of wake effects and power production for a group of large wind turbines  

DOE Green Energy (OSTI)

Data from a group of three MOD-2 wind turbines and two meteorological towers at Goodnoe Hills were analyzed to evaluate turbine power output and wake effects (losses in power production due to operation of upwind turbines), and atmospheric factors influencing them. The influences of variations in the ambient wind speed, wind direction, and turbulence intensity were the primary factors evaluated. Meteorological and turbine data collected at the Goodnoe Hills site from April 1 to October 17, 1985, were examined to select the data sets for these analyses. Wind data from the two meteorological towers were evaluated to estimate the effect of a wake from an upwind turbine on the wind flow measured at the downwind tower. Maximum velocity deficits were about 25% and 12% at downwind distances of 5.8 and 8.3 rotor diameters (D), respectively. However, the maximum deficits at 5.8 D were about 14/degree/ off the centerline orientation between the turbine and the tower, indicating significant wake curvature. Velocity deficits were found to depend on the ambient wind speed, ranging from 27% at lower speeds (15 to 25 mph) to 20% at higher speeds (30 to 35 mph). Turbulence intensity increases dramatically in the wake by factors of about 2.3 and 1.5 over ambient conditions at 5.8 D and 8.3 D, respectively. An analysis of the ambient (non-wake) power production for all three turbines showed that the MOD-2 power output depends, not only on wind speed, but also on the turbulence intensity. At wind speeds below rated, there was a dramatic difference in turbine power output between low and high turbulence intensities for the same wind speed. One of the turbines had vortex generators on the blades. This turbine produced from 10% to 13% more power than the other two turbines when speeds were from 24 to 31 mph. 11 refs., 21 figs., 2 tabs.

Elliott, D.L.; Buck, J.W.; Barnard, J.C.

1988-04-01T23:59:59.000Z

417

Wind energy manual  

E-Print Network (OSTI)

Objectives: The course introduces principles of wind power production, design of wind turbines, location and design of wind farms, control of turbines and wind farms, predictive modeling, diagnostics, operations and maintenance, condition monitoring, health monitoring and of turbine components and systems, wind farm performance optimization, and integration of wind power with a grid. The modeling and analysis aspect of the topics discussed in the class will be illustrated with examples and case studies. Textbook: References:

A. Vieira; Da Rosa; Fundamentals Renewable; Energy Processes; San Diego; Jacob Kirpes; Small Wind

2013-01-01T23:59:59.000Z

418

Turbulent Kinetic Energy in the Oklahoma City Urban Environment  

DOE Green Energy (OSTI)

A major field experiment, Joint URBAN 2003 (JU2003), was conducted in Oklahoma City in July 2003 to collect meteorological and tracer data sets for evaluating dispersion models in urban areas. The Department of Homeland Security and the Defense Threat Reduction Agency were the primary sponsors of JU2003. Investigators from five Department of Energy national laboratories, several other government agencies, universities, private companies, and international agencies conducted the experiment. Observations to characterize the meteorology in and around the urban area complemented the observation of the dispersion of SF6, an inert tracer gas. Over one hundred threedimensional sonic anemometers were deployed in and around the urban area to monitor wind speed, direction, and turbulence fluxes during releases of SF6. Sonic deployment locations included a profile of eight sonic anemometers mounted on a crane less than 1 km north of the central business district (CBD). Using data from these and other sonic anemometers deployed in the urban area, we can quantify the effect of the urban area on atmospheric turbulence and compare results seen in OKC to those in other urban areas to assess the parameters typically used in parameterizations of urban turbulence.

Lundquist, J; Leach, M; Gouveia, F

2004-06-24T23:59:59.000Z

419

NREL: Wind Research - Testing  

NLE Websites -- All DOE Office Websites (Extended Search)

Testing Photo of a large wind turbine blade sticking out of the structural testing laboratory; it is perpendicular to a building at the National Wind Technology Center. A...

420

Wind | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Assessment and Characterization Defining, measuring, and forecasting land-based and offshore wind resources Environmental Impacts and Siting of Wind Projects Avoiding,...

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Wind/Hydro Study  

NLE Websites -- All DOE Office Websites (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...

422

Wind Energy Technologies  

Energy.gov (U.S. Department of Energy (DOE))

Wind energy technologies use the energy in wind for practical purposes such as generating electricity, charging batteries, pumping water, and grinding grain.

423

Wind for Schools (Poster)  

SciTech Connect

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.

Baring-Gould, I.

2010-05-01T23:59:59.000Z

424

Wind for Schools (Poster)  

SciTech Connect

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.

Baring-Gould, I.

2010-05-01T23:59:59.000Z

425

Wind energy bibliography  

DOE Green Energy (OSTI)

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.

None

1995-05-01T23:59:59.000Z

426

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network (OSTI)

policy support for other renewable energy sources, wind mayrenewable energy and climate policy initiatives. With wind

Bolinger, Mark

2010-01-01T23:59:59.000Z

427

U.S. Virgin Islands - Solar and Wind Easements and Rights Laws | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

U.S. Virgin Islands - Solar and Wind Easements and Rights Laws U.S. Virgin Islands - Solar and Wind Easements and Rights Laws U.S. Virgin Islands - Solar and Wind Easements and Rights Laws < Back Eligibility Commercial Fed. Government Industrial Institutional Local Government Nonprofit Residential Schools State Government Savings Category Solar Buying & Making Electricity Heating & Cooling Commercial Heating & Cooling Heating Water Heating Wind Program Info Program Type Solar/Wind Access Policy 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 defined as "any system that converts, stores, collects, protects or distributes the kinetic energy of the sun or wind into mechanical, chemical or electrical energy to provide

428

Role Based Access Control  

Science Conference Proceedings (OSTI)

... Nash and Poland [10] discuss the application of role based access control to cryptographic authentication devices commonly used in the banking ...

429

Access Grid - CECM  

E-Print Network (OSTI)

"The Access Grid (AG) is the ensemble of resources that can be used to support ... We shall also illustrate the basic capture capacities that Smart Technology's ...

430

Science Open Access Journals  

Office of Scientific and Technical Information (OSTI)

SOAJ allows the user to search multiple open access publications with a single query. Results are consolidated and returned in relevance-ranked order, and users are...

431

Making VRML Accessible  

Science Conference Proceedings (OSTI)

... Paper - Making VRML Accessible for People with Disabilities by Sandy Ressler and Qiming Wang to Appear in Proceeding of ASSETS 98. ...

432

Diablo Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

Diablo Winds Wind Farm Diablo Winds Wind Farm Facility Diablo Winds Wind Farm Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner NextEra Energy Resources Developer NextEra Energy Resources Energy Purchaser Pacific Gas & Electric Co Location Altamont Pass CA Coordinates 37.7347°, -121.652° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.7347,"lon":-121.652,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

433

NREL: Wind Research - Offshore Wind Resource Characterization  

NLE Websites -- All DOE Office Websites (Extended Search)

Offshore Wind Resource Characterization Offshore Wind Resource Characterization Map of the United States, showing the wind potential of offshore areas across the country. Enlarge image US offshore wind speed estimates at 90-m height NREL scientists and engineers are leading efforts in resource mapping, remote sensor measurement and development, and forecasting that are essential for the development of offshore wind. Resource Mapping For more than 15 years, NREL's meteorologists, engineers, and Geographic Information System experts have led the production of wind resource characterization maps and reports used by policy makers, private industry, and other government organizations to inform and accelerate the development of wind energy in the United States. Offshore wind resource data and mapping has strategic uses. As with terrestrial developments, traditional

434

NREL: Wind Research - Midsize Wind Turbine Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Midsize Wind Turbine Research Midsize Wind Turbine Research To facilitate the development and commercialization of midsize wind turbines (turbines with a capacity rating of more than 100 kW up to 1 MW), the U.S. Department of Energy (DOE) and NREL launched the Midsize Wind Turbine Development Project. In its latest study, NREL determined that there is a substantial market for midsize wind turbines. One of the most significant barriers to the midsize turbine market is the lack of turbines available for deployment; there are few midsize turbines on the market today. The objectives of the Midsize Wind Turbine Development Project are to reduce the barriers to wind energy expansion by filling an existing domestic technology gap; facilitate partnerships; accelerate maturation of existing U.S. wind energy businesses; and incorporate process improvement

435

Commonwealth Wind Incentive Program – Micro Wind Initiative  

Energy.gov (U.S. Department of Energy (DOE))

Through the Commonwealth Wind Incentive Program – Micro Wind Initiative the Massachusetts Clean Energy Center (MassCEC) offers rebates of up to $4/W with a maximum of $130,000 for design and...

436

Wind Power Today: Federal Wind Program Highlights  

DOE Green Energy (OSTI)

Wind Power Today is an annual publication that provides an overview of the wind research conducted under the U.S. Department of Energy's Wind and Hydropower Technologies Program. The purpose of Wind Power Today is to show how DOE supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy. Content objectives include: educate readers about the advantages and potential for widespread deployment of wind energy; explain the program's objectives and goals; describe the program's accomplishments in research and application; examine the barriers to widespread deployment; describe the benefits of continued research and development; facilitate technology transfer; and attract cooperative wind energy projects with industry.

Not Available

2005-04-01T23:59:59.000Z

437

Mid-Size Wind Turbines | Open Energy Information  

Open Energy Info (EERE)

Page Page Edit History Facebook icon Twitter icon » Mid-Size Wind Turbines Jump to: navigation, search A Vergnet GEV MP C 275-kW turbine at the Sandywoods Community, Rhode island. Photo from Stefan Dominioni/Vergnet S.A., NREL 26490. The U.S. Department of Energy defines mid-size wind turbines as 101 kilowatts to 1 megawatt.[1] Resources Kwartin, R.; Wolfrum, A.; Granfield, K.; Kagel, A.; Appleton, A. (2008). An Analysis of the Technical and Economic Potential for Mid-Scale Distributed Wind. National Renewable Energy Laboratory. Accessed September 27, 2013. National Renewable Energy Laboratory. Midsize Wind Turbine Research. Accessed September 27, 2013. This webpage discusses efforts to develop and commercialize mid-size wind turbines in the United States. References

438

Wind Workforce Development | Open Energy Information  

Open Energy Info (EERE)

Workforce Development Workforce Development Jump to: navigation, search Photo from Casey Joyce, RMT Inc., NREL 24542 If the wind industry and nation wish to capitalize on industry growth, reversing current educational trends away from science, engineering, and technical skills must be achieved.[1] The following resources explore this topic. Resources Baring-Gould, I.; Kelly, M. (2010). Wind Energy Workforce Development: A Roadmap to a Sustainable Wind Industry. National Renewable Energy Laboratory. Accessed August 26, 2013. This poster provides an overview of the educational infrastructure and expected industry needs through a discussion of the activities to train workers while addressing issues for each of the education sectors, leading to the development of an educational infrastructure to support wind

439

Wind Energy Community Acceptance | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Wind Energy Community Acceptance Jump to: navigation, search In 2012 in Lamar, Colorado, Bob Emick (center, back to camera and Greg Emich (right in cowboy hat) talk about the 98 1.5-megawatt wind turbines on their ranch. Photo by Dennis Schroeder, NREL 21768 The following resources address community acceptance topics. Baring-Gould, I. (June 5, 2012). Social Acceptance of Wind Energy: Managing and Evaluating Its Market Impacts. National Renewable Energy Laboratory. Accessed August 14, 2013. This presentation offers background information on social acceptance issues, results of surveys conducted by the New England Wind Forum at a

440

Offshore Wind Resource | OpenEI  

Open Energy Info (EERE)

Offshore Wind Resource Offshore Wind Resource Dataset Summary Description Global Wind Potential Supply Curves by Country, Class, and Depth (quantities in GW) Source National Renewable Energy Laboratory Date Released July 12th, 2012 (2 years ago) Date Updated July 12th, 2012 (2 years ago) Keywords offshore resource offshore wind renewable energy potential Data application/vnd.openxmlformats-officedocument.spreadsheetml.sheet icon offshore_resource_100_vs2.xlsx (xlsx, 41.7 KiB) Quality Metrics Level of Review Peer Reviewed Comment Temporal and Spatial Coverage Frequency Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Dust Motions Driven by MHD Turbulence  

E-Print Network (OSTI)

We discuss the relative grain motions due to MHD turbulence in interstellar medium. It has been known for decades that turbulent drag is an efficient way to induce grain relative motions. However, earlier treatments disregarded magnetic field and used Kolmogorov turbulence. Unlike hydro turbulence, MHD turbulence is anisotropic on small scales. Moreover, compressible modes are important for MHD and magnetic perturbations can directly interact with grains. We provide calculations of grain relative motion for realistic interstellar turbulence driving that is consistent with the velocity dispersions observed in diffuse gas and for realistic grain charging. We account for the turbulence cutoff arising from abmipolar drag. Our results on grain shattering are consistent with the customary accepted cutoff size. We obtain grain velocities for turbulence with parameters consistent with those in HI and dark clouds. These velocities are smaller than those in earlier papers, where MHD effects were disregarded. Finally, w...

Lazarian, A; Yan, Huirong

2002-01-01T23:59:59.000Z

442

Turbulent Kinetic Energy Budgets over Mountainous Terrain  

Science Conference Proceedings (OSTI)

The objective of this study is to describe the characteristics of the airflow and turbulence structure over mountainous terrain. Turbulent characteristics of the airflow were measured using well-instrumented aircraft. The shear, buoyancy, ...

Theodore S. Karacostas; John D. Marwitz

1980-02-01T23:59:59.000Z

443

Strong Turbulence in the Wave Crest Region  

Science Conference Proceedings (OSTI)

High-resolution vertical velocity profiles in the surface layer of a lake reveal the turbulence structure beneath strongly forced waves. Dissipation rates of turbulence kinetic energy are estimated based on centered second-order structure ...

Johannes Gemmrich

2010-03-01T23:59:59.000Z

444

Turbulent Mixing in Stably Stratified Shear Flows  

Science Conference Proceedings (OSTI)

Vertical mixing of momentum and heat is investigated in turbulent stratified shear flows. It is assumed that the flow has uniform shear and stratification with homogeneous turbulence and that an equilibrium is reached between kinetic and ...

U. Schumann; T. Gerz

1995-01-01T23:59:59.000Z

445

The Canopy Horizontal Array Turbulence Study  

Science Conference Proceedings (OSTI)

The Canopy Horizontal Array Turbulence Study (CHATS) took place in spring 2007 and is the third in the series of Horizontal Array Turbulence Study (HATS) experiments. The HATS experiments have been instrumental in testing and developing subfilterscale (...

Edward G. Patton; Thomas W. Horst; Peter P. Sullivan; Donald H. Lenschow; Steven P. Oncley; William O. J. Brown; Sean P. Burns; Alex B. Guenther; Andreas Held; Thomas Karl; Shane D. Mayor; Luciana V. Rizzo; Scott M. Spuler; Jielun Sun; Andrew A. Turnipseed; Eugene J. Allwine; Steven L. Edburg; Brian K. Lamb; Roni Avissar; Ronald J. Calhoun; Jan Kleissl; William J. Massman; Kyaw Tha Paw U; Jeffrey C. Weil

2011-05-01T23:59:59.000Z

446

UNSTEADY SIMULATION OF FLOW IN MICRO VERTICAL AXIS WIND TURBINE  

E-Print Network (OSTI)

Though wind turbines and windmills have been used for centuries, the application of aerodynamics technology to improve reliability and reduce costs of wind-generated energy has only been pursued in earnest for the past 40 years. Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source. Power production from wind turbines is affected by certain conditions: wind speed, turbine speed, turbulence and the changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the nacelle’s one. Due to this combination of movements, flow around this turbine can be more highly unsteady, because of great blade stagger angles. The turbine has a rotor with three straight blades of symmetrical airfoil. Paper presents unsteady simulations that have been performed for one wind velocity, and different initial blades stagger angles. The influence of interaction of blades is studied for one specific constant rotational speed among the four rotational speeds that have been studied.

A. C. Bayeul-lainé; G. Bois

2013-01-01T23:59:59.000Z

447

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

DOE Green Energy (OSTI)

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.

Milligan, M.R.; Artig, R.

1999-07-08T23:59:59.000Z

448

Accessibility validation with RAVEN  

Science Conference Proceedings (OSTI)

Testing is, for most, a necessary evil in the software life cycle. One very important form of testing is the evaluation of software products according to mandated criteria or guidelines such as those that specify level of accessibility. Such evaluations ... Keywords: AOP, GUI, Java, accessibility, reflection, rich-client

Barry Feigenbaum; Michael Squillace

2006-05-01T23:59:59.000Z

449

Passive load control for large wind turbines.  

DOE Green Energy (OSTI)

Wind energy research activities at Sandia National Laboratories focus on developing large rotors that are lighter and more cost-effective than those designed with current technologies. Because gravity scales as the cube of the blade length, gravity loads become a constraining design factor for very large blades. Efforts to passively reduce turbulent loading has shown significant potential to reduce blade weight and capture more energy. Research in passive load reduction for wind turbines began at Sandia in the late 1990's and has moved from analytical studies to blade applications. This paper discusses the test results of two Sandia prototype research blades that incorporate load reduction techniques. The TX-100 is a 9-m long blade that induces bend-twist coupling with the use of off-axis carbon in the skin. The STAR blade is a 27-m long blade that induces bend-twist coupling by sweeping the blade in a geometric fashion.

Ashwill, Thomas D.

2010-05-01T23:59:59.000Z

450

Accessing HPSS at NERSC  

NLE Websites -- All DOE Office Websites (Extended Search)

Accessing HPSS Accessing HPSS Accessing HPSS Once you have successfully generated an HPSS token you can access NERSC's HPSS in the different ways listed below. HSI and HTAR are usually the best ways to transfer data in and out of HPSS but other methods are also included. Access Method When to use this method Features Limitations HSI When a full-featured unix-like interface is desired high performance (parallel); unix-like user interface; firewall mode client is specific to HPSS version and might not work at other sites; HTAR When you have large collections of smaller (~10MB or less) files high performance (parallel); creates a tar file directly in HPSS along with an index file; more efficient for large collections of file same client limitations as HSI; also does not have firewall mode so using on a remote site with a firewall will require modification of firewall rules

451

WindWaveFloat Final Report  

Science Conference Proceedings (OSTI)

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.

Alla Weinstein, Dominique Roddier, Kevin Banister

2012-03-30T23:59:59.000Z

452

Intermittent Dissipation and Local Heating in the Solar Wind  

E-Print Network (OSTI)

Evidence for inhomogeneous heating in the interplanetary plasma near current sheets dynamically generated by magnetohydrodynamic (MHD) turbulence is obtained using measurements from the ACE spacecraft. These coherent structures only constitute 19% of the data, but contribute 50% of the total plasma internal energy. Intermittent heating manifests as elevations in proton temperature near current sheets, resulting in regional heating and temperature enhancements extending over several hours. The number density of non-Gaussian structures is found to be proportional to the mean proton temperature and solar wind speed. These results suggest magnetofluid turbulence drives intermittent dissipation through a hierarchy of coherent structures, which collectively could be a significant source of coronal and solar wind heating.

Osman, K T; Wan, M; Rappazzo, A F

2011-01-01T23:59:59.000Z

453

Pennsylvania Capital Access Program (Pennsylvania) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Pennsylvania Capital Access Program (Pennsylvania) Pennsylvania Capital Access Program (Pennsylvania) Pennsylvania Capital Access Program (Pennsylvania) < Back Eligibility Agricultural Commercial Construction Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info Funding Source Pennsylvania Economic Development Financing Authority (PEDFA) State Pennsylvania Program Type

454

Capital Access Program (CAP) (Michigan) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

CAP) (Michigan) CAP) (Michigan) Capital Access Program (CAP) (Michigan) < Back Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Residential Installer/Contractor Rural Electric Cooperative Tribal Government Low-Income Residential Schools Retail Supplier Institutional Multi-Family Residential Systems Integrator Fuel Distributor Nonprofit General Public/Consumer Transportation Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Michigan Program Type Loan Program The Capital Access Program (CAP), utilizes public resources to generate private financing for small business in Michigan seeking access to capital.

455

Stimulated Neutrino Transformation Through Turbulence  

E-Print Network (OSTI)

We derive an analytical solution for the flavor evolution of a neutrino through a turbulent density profile which is found to accurately predict the amplitude and transition wavelength of numerical solutions on a case-by-case basis. The evolution is seen to strongly depend upon those Fourier modes in the turbulence which are approximately the same as the splitting between neutrino eigenvalues and, unexpectedly, we also find a dependence upon the long wavelength modes when the ratio of their amplitude and the wavenumber is of order, or greater than, the first root of the Bessel function $J_0$.

Kelly M. Patton; James P. Kneller; Gail C. McLaughlin

2013-10-21T23:59:59.000Z

456

Defining the normal turbine inflow within a wind park environment  

DOE Green Energy (OSTI)

This brief paper discusses factors that must be considered when defining the [open quotes]normal[close quotes] (as opposed to [open quotes]extreme[close quotes]) loading conditions seen in wind turbines operating within a wind park environment. The author defines the [open quotes]normal[close quotes] conditions to include fatigue damage accumulation as a result of: (1) start/stop cycles, (2) emergency shutdowns, and (3) the turbulence environment associated with site and turbine location. He also interprets [open quotes]extreme[close quotes] loading conditions to include those events that can challenge the survivability of the turbine.

Kelley, N.D.

1993-06-01T23:59:59.000Z

457

Defining the normal turbine inflow within a wind park environment  

DOE Green Energy (OSTI)

This brief paper discusses factors that must be considered when defining the {open_quotes}normal{close_quotes} (as opposed to {open_quotes}extreme{close_quotes}) loading conditions seen in wind turbines operating within a wind park environment. The author defines the {open_quotes}normal{close_quotes} conditions to include fatigue damage accumulation as a result of: (1) start/stop cycles, (2) emergency shutdowns, and (3) the turbulence environment associated with site and turbine location. He also interprets {open_quotes}extreme{close_quotes} loading conditions to include those events that can challenge the survivability of the turbine.

Kelley, N.D.

1993-06-01T23:59:59.000Z

458

Applications: Operational wind turbines  

E-Print Network (OSTI)

Capability Applications: Operational wind turbines Benefits: Optimize wind turbine performance Summary: Researchers at the Los Alamos National Laboratory (LANL) Intelligent Wind Turbine Program are developing a multi-physics modeling approach for the analysis of wind turbines in the presence of realistic

459

Wind powering America: Iowa  

DOE Green Energy (OSTI)

Wind resources in the state of Iowa show great potential for wind energy development. This fact sheet provides a brief description of the state's wind resources and the financial incentives available for the development of wind energy systems. It also provides a list of contacts for more information.

NREL

2000-04-11T23:59:59.000Z

460

West Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

West Winds Wind Farm West Winds Wind Farm Facility West Winds Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Caithness Developer SeaWest Energy Purchaser Southern California Edison/PacifiCorp Location San Gorgonio CA Coordinates 33.9095°, -116.734° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.9095,"lon":-116.734,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

Note: This page contains sample records for the topic "accessibility wind turbulence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

New England Wind Forum: New England Wind Resources  

Wind Powering America (EERE)

New England Wind Forum About the New England Wind Forum New England Wind Energy Education Project Historic Wind Development in New England State Activities Projects in New England Building Wind Energy in New England Wind Resources Wind Power Technology Economics Markets Siting Policy Technical Challenges Issues Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share New England Wind Resources Go to the Vermont wind resource map. Go to the New Hampshire wind resource map. Go to the Maine wind resource map. Go to the Massachusetts wind resource map. Go to the Connecticut wind resource map. Go to the Rhode Island wind resource map. New England Wind Resource Maps Wind resources maps of Connecticut, Massachusetts, Maine, New Hampshire, Rhode Island, and Vermont.

462

Wind energy, offers considerable promise: the wind itself is free,  

E-Print Network (OSTI)

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

Langendoen, Koen

463

City of Madison - Solar & Wind Access and Planning Laws (Wisconsin...  

Open Energy Info (EERE)

Category Renewable Energy Incentive Programs Website http:www.cityofmadison.comSustainabilityCitymadiSUNstep.cfm Date added to DSIRE 2000-01-01 Last DSIRE Review 11142012...

464

Wind Powering America  

Wind Powering America (EERE)

These news items are notable additions These news items are notable additions to the Wind Powering America Web site. The Wind Powering America Web site reports recent national and state wind market changes by cataloging wind activities such as wind resource maps, small wind consumer's guides, local wind workshops, news articles, and publications in the areas of policy, public power, small wind, Native Americans, agricultural sector, economic development, public lands, and schools. en-us julie.jones@nrel.gov (Julie Jones) http://www.windpoweringamerica.gov/images/wpa_logo_sm.jpg Wind Powering America http://www.windpoweringamerica.gov/ Nominate an Electric Cooperative for Wind Power Leadership Award by January 15 http://www.windpoweringamerica.gov/filter_detail.asp?itemid=4076 http://www.windpoweringamerica.gov/filter_detail.asp?itemid=4076 Mon, 16

465

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

SciTech Connect

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.

Toole, Gasper L. [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

466

NREL: Wind Research - Small Wind Site Assessment: Wind Powering...  

NLE Websites -- All DOE Office Websites (Extended Search)

environmental impacts have increased the demand for small wind energy systems for homeowners, schools, businesses, and local governments. Over the past decade, the knowledge,...

467

Wind Power Outlook 2004  

DOE Green Energy (OSTI)

The brochure, expected to be updated annually, provides the American Wind Energy Association's (AWAE's) up-to-date assessment of the wind industry. It provides a summary of the state of wind power in the U.S., including the challenges and opportunities facing the industry. It provides summary information on the growth of the industry, policy-related factors such as the federal wind energy production tax credit status, comparisons with natural gas, and public views on wind energy.

anon.

2004-01-01T23:59:59.000Z

468

Wind Resource Maps (Postcard)  

DOE Green Energy (OSTI)

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.

Not Available

2011-07-01T23:59:59.000Z

469

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...

470

NREL: Wind Research - Wind Applications Center Valuable Resource...  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Applications Center Valuable Resource for Wind for Schools Partners March 14, 2013 Audio with Jerry Hudgins, Nebraska Wind Applications Center Director and Joel Jacobs,...

471

Wind Powering America Webinar: Wind Power Economics: Past, Present...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Power Economics: Past, Present, and Future Trends Wind Powering America Webinar: Wind Power Economics: Past, Present, and Future Trends November 23, 2011 - 1:43pm Addthis Wind...

472

NREL: Wind Research - Small Wind Turbine Independent Testing  

NLE Websites -- All DOE Office Websites (Extended Search)

Wind Research Search More Search Options Site Map Printable Version Small Wind Turbine Independent Testing One of the barriers for the small wind market has been the lack...

473

Discussion of “Ultimate Wind Load Design Gust Wind Speeds ...  

Science Conference Proceedings (OSTI)

... Ind. Aerodyn., 97(3–4), 120–131. Peterka, JA (2001). “Database of peak gust wind speeds, Texas Tech/ CSU.” Extreme winds and wind effects on ...

2013-08-19T23:59:59.000Z

474

Surface wind speed distributions| Implications for climate and wind power.  

E-Print Network (OSTI)

?? Surface constituent and energy fluxes, and wind power depend non-linearly on wind speed and are sensitive to the tails of the wind distribution. Until… (more)

Capps, Scott Blair

2010-01-01T23:59:59.000Z

475

Virginia Capital Access Program (Virginia) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Capital Access Program (Virginia) Capital Access Program (Virginia) Virginia Capital Access Program (Virginia) < Back Eligibility Commercial Industrial Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Virginia Program Type Loan Program Provider Virginia Economic Development Partnership The Virginia Capital Access Program (CAP), in partnership with Virginia's Small Business Financing Authority, provides access to capital for small businesses. Businesses must apply to participating banks for a traditional loan, and the lender advises the company of enrollment in CAP. The program offers loan guarantees on a portfolio of loans through a loan loss reserve, which it establishes at each participating bank. Funds can be used for

476

City of Sebastopol - Solar Access | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Sebastopol - Solar Access Sebastopol - Solar Access City of Sebastopol - Solar Access < Back Eligibility Local Government Savings Category Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Water Heating Program Info State California Program Type Solar/Wind Access Policy Provider City of Sebastopol As a condition of approval of a property subdivision parcel map, the City of Sebastopol has the right to ask for dedication of solar easements for the purpose of assuring that each parcel or unit in the subdivision receives sunlight for any solar energy system. Sebastopol also has the right to place restrictions on vegetation or building that would interfere with solar access. These easements can be required as long as they do not reduce allowable densities or the percentage of a lot that can be occupied

477

Marin County - Solar Access Code | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Marin County - Solar Access Code Marin County - Solar Access Code Marin County - Solar Access Code < Back Eligibility Commercial Industrial Residential Savings Category Heating & Cooling Commercial Heating & Cooling Solar Heating Program Info State California Program Type Solar/Wind Access Policy Provider Marin County Community Development Agency Marin County's Energy Conservation Code is designed to assure new subdivisions provide for future passive or natural heating or cooling opportunities in the subdivision to the extent feasible. Streets, lots, and building setbacks must be designed so that habitable buildings are oriented with their long axis running east to west (with a possible variation of thirty degrees to the southwest and thirty degrees to the southeast) for the purpose of solar access. The planning director or planning commission

478

Beta dependence of electron heating in decaying whistler turbulence: Particle-in-cell simulations  

SciTech Connect

Two-dimensional particle-in-cell simulations have been carried out to study electron beta dependence of decaying whistler turbulence and electron heating in a homogeneous, collisionless magnetized plasma. Initially, applied whistler fluctuations at relatively long wavelengths cascade their energy into shorter wavelengths. This cascade leads to whistler turbulence with anisotropic wavenumber spectra which are broader in directions perpendicular to the background magnetic field than in the parallel direction. Comparing the development of whistler turbulence at different electron beta values, it is found that both the wavenumber spectrum anisotropy and electron heating anisotropy decrease with increasing electron beta. This indicates that higher electron beta reduces the perpendicular energy cascade of whistler turbulence. Fluctuation energy dissipation by electron Landau damping responsible for the electron parallel heating becomes weaker at higher electron beta, which leads to more isotropic heating. It suggests that electron kinetic processes are important in determining the properties of whistler turbulence. This kinetic property is applied to discuss the generation of suprathermal strahl electron distributions in the solar wind.

Saito, S. [National Institute of Information and Communications Technology 4-2-1, Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan); Peter Gary, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-01-15T23:59:59.000Z

479

Simulating the effects of upstream turbulence on dispersion around a building  

SciTech Connect

The effects of high turbulence versus no turbulence in a sheared boundary-layer flow approaching a building are being investigated by a turbulent kinetic energy/dissipation model (TEMPEST). The effects on both the mean flow and the concentration field around a cubical building are presented. The numerical simulations demonstrate significant effects due to the differences in the incident flow. The addition of upstream turbulence results in a reduced size of the cavity directly behind the building. The velocity deficits in the wake strongly depend on the upstream turbulence intensities. The accuracy of numerical simulations is verified by comparing the predicted mean flow and concentration fields with the wind tunnel measurements of Castro and Robins (1977) and Robins and Castro (1977, 1975). Comparing the results with experimental data, the authors show that the TEMPEST model can reasonably simulate the mean flow. The numerical simulations of the concentration fields due to a source on the roof-top of the building are presented. Both the value and the position of the maximum ground-level concentration are changed dramatically due to the effects of the upstream level of turblence.

Zhang, Y.Q.; Arya, S.P.S.; Huber, A.H.; Snyder, W.H.

1992-01-01T23:59:59.000Z

480

IMPROVEMENT OF THE WIND FARM MODEL FLAP FOR OFFSHORE APPLICATIONS Bernhard Lange(1), Hans-Peter Waldl(1)(2), Rebecca Barthelmie(3), Algert Gil Guerrero(1)(4), Detlev Heinemann(1)  

E-Print Network (OSTI)

Vindeby. Vertical wake profiles and mean turbulence intensities in the wake were compared for 32 scenarios. Additionally, an estimation of turbulence intensity in the wind farm is essential for the load assumptions used speed profile. It also has important consequences for the modelling of the wake since it leads to a low