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Note: This page contains sample records for the topic "temperature turbulence wind" 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.


1

Predicted Impacts of Proton Temperature Anisotropy on Solar Wind Turbulence  

E-Print Network [OSTI]

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

Klein, Kristopher G

2015-01-01T23:59:59.000Z

2

Solar wind versus magnetosheath turbulence.  

E-Print Network [OSTI]

order statistics (Number of data points ~ 105) 22 4 !" !" = # # # $ $ b b F ! ! " ! # )()( tbtb bSolar wind versus magnetosheath turbulence. Observations of Alfven vortices. O. Alexandrova A properties of turbulence (hydrodynamics) is independent on the energy injection & dissipation energy

Demoulin, Pascal

3

Supercomputers Capture Turbulence in the Solar Wind  

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

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

4

Residual Energy Spectrum of Solar Wind Turbulence  

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

5

Cross-Scale Effects in Solar-Wind Turbulence  

SciTech Connect (OSTI)

The understanding of the small-scale termination of the turbulent energy cascade in collisionless plasmas is nowadays one of the outstanding problems in space physics. In the absence of collisional viscosity, the dynamics at small scales is presumably kinetic in nature; the identification of the physical mechanism which replaces energy dissipation and establishes the link between macroscopic and microscopic scales would open a new scenario in the study of turbulent heating in space plasmas. We present a numerical analysis of kinetic effects along the turbulent energy cascade in solar-wind plasmas which provides an effective unified interpretation of a wide set of spacecraft observations and shows that, simultaneously with an increase in the ion perpendicular temperature, strong bursts of electrostatic activity in the form of ion-acoustic turbulence are produced together with accelerated beams in the ion distribution function.

Valentini, F.; Veltri, P. [Dipartimento di Fisica and CNISM, Universita della Calabria, 87036 Rende (Serbia and Montenegro) (Italy); Califano, F. [Dipartimento di Fisica and CNISM, Universita di Pisa, 56127 Pisa (Italy); Mangeney, A. [Observatoire de Paris-Meudon, 92195 Meudon Cedex (France)

2008-07-11T23:59:59.000Z

6

AIAA980057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS  

E-Print Network [OSTI]

AIAA­98­0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS: PARAMETRIC STUDY WITH MULTIPLE that is most useful in estimating fatigue loads on wind turbine blades. The histograms of rainflow counted turbulence measures---can be used to estimate fatigue loads on wind turbine blades. We first de­ scribe

Sweetman, Bert

7

Physics of Stratocumulus Top (POST): turbulent mixing across capping inversion  

E-Print Network [OSTI]

vertical water potential horizontal wind, and turbulentof potential components of horizontal wind, and buoyantwater potential temperature, horizontal wind, and turbulent

2013-01-01T23:59:59.000Z

8

NACA0015 Measurements in LM Wind Tunnel and Turbulence  

E-Print Network [OSTI]

NACA0015 Measurements in LM Wind Tunnel and Turbulence Generated Noise Franck Bertagnolio Risø, Denmark November 2008 #12;Author: Franck Bertagnolio Title: NACA0015 Measurements in LM Wind Tunnel on its surface and measured in the wind tunnel at LM Glasfiber at various inflow speeds, angles of attack

9

Wind Energy Applications of Unified and Dynamic Turbulence Models  

E-Print Network [OSTI]

Wind Energy Applications of Unified and Dynamic Turbulence Models Stefan Heinz and Harish Gopalan applicable as a low cost alternative. 1 Introduction There is a growing interest in using wind energy suggests the possibility of providing 20% of the electricity in the U.S. by wind energy in 2030

Heinz, Stefan

10

ATMOSPHERIC TURBULENCE MODELING AND IMPLICATIONS FOR WIND ENERGY  

E-Print Network [OSTI]

turbines off too early in high winds, or may risk severe damage to the rotors and blades by operating under Introduction Wind turbines sit at the very bottom of the at- mospheric boundary layer, where winds are highly turbulent, shear events are intermittent, and land- atmosphere interactions may be strong. Turbine hub

Chow, Fotini Katopodes

11

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

E-Print Network [OSTI]

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

Heinemann, Detlev

12

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

E-Print Network [OSTI]

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

Heinemann, Detlev

13

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

E-Print Network [OSTI]

Turbulence of the Solar Wind Studies of the Solar Wind Using the ACE and Helios Spacecraft Bejamin;Abstract The solar wind is a supersonic ow of plasma emanating from the sun and traveling through the interplanetary medium to the outermost reaches of the heliosphere. The solar wind experiences in situ

14

COLLISIONLESS DAMPING AT ELECTRON SCALES IN SOLAR WIND TURBULENCE  

SciTech Connect (OSTI)

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

15

A Dynamical Model of Plasma Turbulence in the Solar Wind  

E-Print Network [OSTI]

A dynamical approach, rather than the usual statistical approach, is taken to explore the physical mechanisms underlying the nonlinear transfer of energy, the damping of the turbulent fluctuations, and the development of coherent structures in kinetic plasma turbulence. It is argued that the linear and nonlinear dynamics of Alfven waves are responsible, at a very fundamental level, for some of the key qualitative features of plasma turbulence that distinguish it from hydrodynamic turbulence, including the anisotropic cascade of energy and the development of current sheets at small scales. The first dynamical model of kinetic turbulence in the weakly collisional solar wind plasma that combines self-consistently the physics of Alfven waves with the development of small-scale current sheets is presented and its physical implications are discussed. This model leads to a simplified perspective on the nature of turbulence in a weakly collisional plasma: the nonlinear interactions responsible for the turbulent casca...

Howes, G G

2015-01-01T23:59:59.000Z

16

Compressive turbulent cascade and heating in the solar wind  

SciTech Connect (OSTI)

A turbulent energy cascade has been recently identified in high-latitude solar wind data samples by using a Yaglom-like relation. However, analogous scaling law, suitably modified to take into account compressible fluctuations, has been observed in a much more extended fraction of the same data set recorded by the Ulysses spacecraft. Thus, it seems that large scale density fluctuations, despite their low amplitude, play a major role in the basic scaling properties of turbulence. The compressive turbulent cascade, moreover, seems to be able to supply the energy needed to account for the local heating of the non-adiabatic solar wind.

Marino, R. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Sorriso-Valvo, L. [Liquid Crystal Laboratory, INFM/CNR, Ponte Bucci 33B, I-87036 Rende (Italy); Carbone, V. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); Noullez, A. [University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Bruno, R. [INAF-Istituto Fisica Spazio Interplanetario, Rome (Italy)

2010-03-25T23:59:59.000Z

17

A turbulence-driven model for heating and acceleration of the fast wind in coronal holes  

E-Print Network [OSTI]

A model is presented for generation of fast solar wind in coronal holes, relying on heating that is dominated by turbulent dissipation of MHD fluctuations transported upwards in the solar atmosphere. Scale-separated transport equations include large-scale fields, transverse Alfvenic fluctuations, and a small compressive dissipation due to parallel shears near the transition region. The model accounts for proton temperature, density, wind speed, and fluctuation amplitude as observed in remote sensing and in situ satellite data.

Verdini, A; Matthaeus, W H; Oughton, S; Dmitruk, P

2009-01-01T23:59:59.000Z

18

ON INTERMITTENT TURBULENCE HEATING OF THE SOLAR WIND: DIFFERENCES BETWEEN TANGENTIAL AND ROTATIONAL DISCONTINUITIES  

SciTech Connect (OSTI)

The intermittent structures in solar wind turbulence, studied by using measurements from the WIND spacecraft, are identified as being mostly rotational discontinuities (RDs) and rarely tangential discontinuities (TDs) based on the technique described by Smith. Only TD-associated current sheets (TCSs) are found to be accompanied with strong local heating of the solar wind plasma. Statistical results show that the TCSs have a distinct tendency to be associated with local enhancements of the proton temperature, density, and plasma beta, and a local decrease of magnetic field magnitude. Conversely, for RDs, our statistical results do not reveal convincing heating effects. These results confirm the notion that dissipation of solar wind turbulence can take place in intermittent or locally isolated small-scale regions which correspond to TCSs. The possibility of heating associated with RDs is discussed.

Wang Xin; Tu Chuanyi; He Jiansen; Wang Linghua [School of Earth and Space Sciences, Peking University, 100871 Beijing (China); Marsch, Eckart, E-mail: chuanyitu@pku.edu.cn [Institute for Experimental and Applied Physics, Christian Albrechts University at Kiel, D-24118 Kiel (Germany)

2013-08-01T23:59:59.000Z

19

Measurement of turbulent wind velocities using a rotating boom apparatus  

SciTech Connect (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

20

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 appears to be consistent with that pertaining to the morphology of the tree branches. An energy criterion shows that the dynamics of the branches is basically passive. The possibility of hydrodynamic screening by the leaves is discussed.

Theo Odijk

2014-07-10T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Turbulent heating of the corona and solar wind: the heliospheric  

E-Print Network [OSTI]

resembles magnetic lines of force Eclipse observations show the `solar corona' Thomson-scattered white light ­ photospheric light scattered from dust, solar spectrum remains ­ `zodiacal light' E corona ­ emission linesTurbulent heating of the corona and solar wind: the heliospheric dark energy problem Stuart D. Bale

22

Reconnection outflow generated turbulence in the solar wind  

E-Print Network [OSTI]

Petschek-type time-dependent reconnection (TDR) and quasi-stationary reconnection (QSR) models are considered to understand reconnection outflow structures and the features of the associated locally generated turbulence in the solar wind. We show that the outflow structures, such as discontinuites, Kelvin-Helmholtz (KH) unstable flux tubes or continuous space filling flows cannot be distinguished from one-point WIND measurements. In both models the reconnection outflows can generate more or less spatially extended turbulent boundary layers (TBDs). The structure of an unique extended reconnection outflow is investigated in detail. The analysis of spectral scalings and break locations show that reconnection outflows can control the local field and plasma conditions which may play in favor of one or another turbulent dissipation mechanisms with their characteristic scales and wavenumbers.

Vrs, Z; Semenov, V S; Zaqarashvili, T V; Bruno, R; Khodachenko, M

2014-01-01T23:59:59.000Z

23

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

24

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

E-Print Network [OSTI]

and more wind turbines become integrated into our electric grids, a proper understanding stress the need for a profound understanding of the physics of turbulence and its impact on wind energyTurbulent Character of Wind Energy Patrick Milan, Matthias Wa¨chter, and Joachim Peinke ForWind

Peinke, Joachim

25

Supercomputers Capture Turbulence in the Solar Wind  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAbout »Lab (NewportSuccess Stories T ECapture Turbulence in

26

Large-eddy simulation of a wind turbine wake in turbulent  

E-Print Network [OSTI]

Large-eddy simulation of a wind turbine wake in turbulent neutral shear flow Shengbai Xie, Cristina-similar velocity profile existing in the wake after a wind turbine? How does the wake influence the vertical? Motivation #12; Large-eddy simulation for turbulent flow field Actuator-line model for wind turbine ui

Firestone, Jeremy

27

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

E-Print Network [OSTI]

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

Manuel, Lance

28

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

29

TURBULENT HEATING OF THE DISTANT SOLAR WIND BY INTERSTELLAR PICKUP PROTONS IN A DECELERATING FLOW  

E-Print Network [OSTI]

Previous models of solar wind heating by interstellar pickup proton-driven turbulence have assumed that the wind speed is a constant in heliocentric radial position. However, the same pickup process, which is taken to ...

Isenberg, Philip A.

30

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

E-Print Network [OSTI]

Electron and proton heating by solar wind turbulence B. Breech,1 W. H. Matthaeus,2 S. R. Cranmer,3. Oughton (2009), Electron and proton heating by solar wind turbulence, J. Geophys. Res., 114, A09103, doi profile, requiring some process(es) to provide additional heat sources. One possible, and successful

Oughton, Sean

31

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

E-Print Network [OSTI]

On the Study of Uncertainty in Inflow Turbulence Model Parameters in Wind Turbine Applications Korn, Austin, TX 78712 In stochastic simulation of inflow turbulence random fields for wind turbine applica models can be in turn highly variable. Turbine load and performance variability could as well result

Manuel, Lance

32

Fine Structure of the Solar Wind Turbulence Inferred from Simultaneous Radio Occultation Observations at  

E-Print Network [OSTI]

Fine Structure of the Solar Wind Turbulence Inferred from Simultaneous Radio Occultation Observations at Widely-Spaced Ground Stations M.K. Bird , P. Janardhan , A.I. Efimov, L.N. Samoznaev, V extended for up to four hours, thereby allowing studies of solar wind turbulence dynamics at spatial scales

Padmanabhan, Janardhan

33

Turbulent electron transport in edge pedestal by electron temperature gradient turbulence  

SciTech Connect (OSTI)

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

Singh, R. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Jhang, Hogun [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); CMTFO and CASS, University of California, San Diego 92093-0424, California (United States)

2013-11-15T23:59:59.000Z

34

Scaling of the electron dissipation range of solar wind turbulence  

E-Print Network [OSTI]

Electron scale solar wind turbulence has attracted great interest in recent years. Clear evidences have been given from the Cluster data that turbulence is not fully dissipated near the proton scale but continues cascading down to the electron scales. However, the scaling of the energy spectra as well as the nature of the plasma modes involved at those small scales are still not fully determined. Here we survey 10 years of the Cluster search-coil magnetometer (SCM) waveforms measured in the solar wind and perform a statistical study of the magnetic energy spectra in the frequency range [$1, 180$]Hz. We show that a large fraction of the spectra exhibit clear breakpoints near the electon gyroscale $\\rho_e$, followed by steeper power-law like spectra. We show that the scaling below the electron breakpoint cannot be determined unambiguously due to instrumental limitations that will be discussed in detail. We compare our results to recent ones reported in other studies and discuss their implication on the physical...

Sahraoui, F; De Patoul, J; Belmont, G; Goldstein, M L; Retino, A; Robert, P; Cornilleau-Wehrlin, N; Canu, P

2013-01-01T23:59:59.000Z

35

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

SciTech Connect (OSTI)

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

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

2014-04-01T23:59:59.000Z

36

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

E-Print Network [OSTI]

AIAA-98-0057 RELATING TURBULENCE TO WIND TURBINE BLADE LOADS: PARAMETRIC STUDY WITH MULTIPLE that is most useful in estimating fatigue loads on wind turbine blades. The histograms of rain ow counted measures|can be used to estimate fatigue loads on wind turbine blades. We rst de- scribe a general approach

Sweetman, Bert

37

The Temperature of Interstellar Clouds from Turbulent Heating  

E-Print Network [OSTI]

To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the dimension of the most dissipative structures. By comparing the model with the probability distribution of the turbulent dissipation rate in a simulation of supersonic and super-Alfvenic turbulence, we find a best-fit value of d=1.64. We apply this intermittency model to the computation of the mass-weighted probability distribution of the gas temperature of molecular clouds, high-mass star-forming cores, and cold diffuse HI clouds. Our main results are: i) The mean gas temperature in molecular clouds can be explained as the effect of turbulent heating alone, while cosmic ray heating may dominate only in regions where the turbulent heating is low; ii) The mean gas temperature in high-mass star-forming cores with typical FWHM of ~6 km/s (corresponding to a 1D rms velocity of 2.5 km/s) may be completely controlled by turbulent heating, which predicts a mean value of approximately 36 K, two to three times larger than the mean gas temperature in the absence of turbulent heating; iii) The intermittency of the turbulent heating can generate enough hot regions in cold diffuse HI clouds to explain the observed CH+ abundance, if the rms velocity on a scale of 1 pc is at least 3 km/s, in agreement with previous results based on incompressible turbulence. Because of its importance in the thermal balance of molecular clouds and high-mass star-forming cores, the process of turbulent heating may be central in setting the characteristic stellar mass and in regulating molecular chemical reactions.

Liubin Pan; Paolo Padoan

2008-06-30T23:59:59.000Z

38

Wind Energy and the Turbulent Nature of the Atmospheric Boundary Layer  

E-Print Network [OSTI]

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

Wchter, Matthias; Hlling, Michael; Morales, Allan; Milan, Patrick; Mcke, Tanja; Peinke, Joachim; Reinke, Nico; Rinn, Philip

2012-01-01T23:59:59.000Z

39

Permutation Entropy and Statistical Complexity Analysis of Turbulence in Laboratory Plasmas and the Solar Wind  

E-Print Network [OSTI]

The Bandt-Pompe permutation entropy and the Jensen-Shannon statistical complexity are used to analyze fluctuating time series of three different plasmas: the magnetohydrodynamic (MHD) turbulence in the plasma wind tunnel of the Swarthmore Spheromak Experiment (SSX), drift-wave turbulence of ion saturation current fluctuations in the edge of the Large Plasma Device (LAPD) and fully-developed turbulent magnetic fluctuations of the solar wind taken from the WIND spacecraft. The entropy and complexity values are presented as coordinates on the CH plane for comparison among the different plasma environments and other fluctuation models. The solar wind is found to have the highest permutation entropy and lowest statistical complexity of the three data sets analyzed. Both laboratory data sets have larger values of statistical complexity, suggesting these systems have fewer degrees of freedom in their fluctuations, with SSX magnetic fluctuations having slightly less complexity than the LAPD edge fluctuations. The CH ...

Weck, Peter J; Brown, Michael R; Wicks, Robert T

2014-01-01T23:59:59.000Z

40

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

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

SciTech Connect (OSTI)

Incompressible and isotropic magnetohydrodynamic turbulence in plasmas 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 Alfvenic state. An analogous phenomenological scaling law, suitably modified to take into account compressible fluctuations, is observed more frequently in the same data set. Large-scale density fluctuations, despite their low amplitude, thus play 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 nonadiabatic solar wind.

Carbone, V. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); Liquid Crystal Laboratory, INFM/CNR, Ponte Bucci 33B, I-87036 Rende (Italy); Marino, R. [Dipartimento di Fisica, Universita della Calabria, Ponte Bucci 31C, I-87036 Rende (Italy); University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Sorriso-Valvo, L. [Liquid Crystal Laboratory, INFM/CNR, Ponte Bucci 33B, I-87036 Rende (Italy); Noullez, A. [University of Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Bruno, R. [Istituto di Fisica dello Spazio Interplanetario-INAF, via Fosso del Cavaliere Roma (Italy)

2009-08-07T23:59:59.000Z

42

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

SciTech Connect (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

43

Probing plasma turbulence by modulating the electron temperature gradient  

E-Print Network [OSTI]

The local value of a/L[subscript Te], a turbulence drive term, was modulated with electron cyclotron heating in L-mode discharges on DIII-D [ J. L. Luxon, Nucl. Fusion 42, 614 (2002) ] and the density and electron temperature ...

DeBoo, J. C.

44

Electron geodesic acoustic modes in electron temperature gradient mode turbulence  

SciTech Connect (OSTI)

In this work, the first demonstration of an electron branch of the geodesic acoustic mode (el-GAM) driven by electron temperature gradient (ETG) modes is presented. The work is based on a fluid description of the ETG mode retaining non-adiabatic ions and the dispersion relation for el-GAMs driven nonlinearly by ETG modes is derived. A new saturation mechanism for ETG turbulence through the interaction with el-GAMs is found, resulting in a significantly enhanced ETG turbulence saturation level compared to the mixing length estimate.

Anderson, Johan; Nordman, Hans [Department of Earth and Space Sciences, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Singh, Raghvendra; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

2012-08-15T23:59:59.000Z

45

Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind  

E-Print Network [OSTI]

upstream of the Earth?s bow shock. The WIND/WAVES thermal noise receiver was specially designed to measureSolar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind the in situ plasma thermal noise spectra, from which the electron density and temperature can be accurately

California at Berkeley, University of

46

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

SciTech Connect (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 {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

47

Short wavelength ion temperature gradient turbulence  

SciTech Connect (OSTI)

The ion temperature gradient (ITG) mode in the high wavenumber regime (k{sub y}{rho}{sub s}>1), referred to as short wavelength ion temperature gradient mode (SWITG) is studied using the nonlinear gyrokinetic electromagnetic code GENE. It is shown that, although the SWITG mode may be linearly more unstable than the standard long wavelength (k{sub y}{rho}{sub s}<1) ITG mode, nonlinearly its contribution to the total thermal ion heat transport is found to be low. We interpret this as resulting from an increased zonal flow shearing effect on the SWITG mode suppression.

Chowdhury, J.; Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar (India); Brunner, S.; Lapillonne, X.; Villard, L. [CRPP, Association EURATOM-Confederation Suisse, EPFL, 1015 Lausanne (Switzerland); Jenko, F. [Max-Planck-Institut fuer Plasmaphysik Boltzmannstr. 2, D-85748 Garching (Germany)

2012-10-15T23:59:59.000Z

48

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

SciTech Connect (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

49

Energy spectra of finite temperature superfluid helium-4 turbulence  

SciTech Connect (OSTI)

A mesoscopic model of finite temperature superfluid helium-4 based on coupled Langevin-Navier-Stokes dynamics is proposed. Drawing upon scaling arguments and available numerical results, a numerical method for designing well resolved, mesoscopic calculations of finite temperature superfluid turbulence is developed. The application of model and numerical method to the problem of fully developed turbulence decay in helium II, indicates that the spectral structure of normal-fluid and superfluid turbulence is significantly more complex than that of turbulence in simple-fluids. Analysis based on a forced flow of helium-4 at 1.3 K, where viscous dissipation in the normal-fluid is compensated by the Lundgren force, indicate three scaling regimes in the normal-fluid, that include the inertial, low wavenumber, Kolmogorov k{sup ?5/3} regime, a sub-turbulence, low Reynolds number, fluctuating k{sup ?2.2} regime, and an intermediate, viscous k{sup ?6} range that connects the two. The k{sup ?2.2} regime is due to normal-fluid forcing by superfluid vortices at high wavenumbers. There are also three scaling regimes in the superfluid, that include a k{sup ?3} range that corresponds to the growth of superfluid vortex instabilities due to mutual-friction action, and an adjacent, low wavenumber, k{sup ?5/3} regime that emerges during the termination of this growth, as superfluid vortices agglomerate between intense normal-fluid vorticity regions, and weakly polarized bundles are formed. There is also evidence of a high wavenumber k{sup ?1} range that corresponds to the probing of individual-vortex velocity fields. The Kelvin waves cascade (the main dynamical effect in zero temperature superfluids) appears to be damped at the intervortex space scale.

Kivotides, Demosthenes [Department of Aeronautics, Imperial College London, London SW7 2AZ (United Kingdom)

2014-10-15T23:59:59.000Z

50

NONLINEAR AERODYNAMIC ANALYSIS OF BRIDGES UNDER TURBULENT WINDS: THE NEW FRONTIER IN BRIDGE  

E-Print Network [OSTI]

NONLINEAR AERODYNAMIC ANALYSIS OF BRIDGES UNDER TURBULENT WINDS: THE NEW FRONTIER IN BRIDGE AERODYNAMICS Xinzhong Chen , Ahsan Kareem and Fred L. Haan, Jr. ¡ Department of Civil Engineering. These approaches are limited to linear structures in which nonlinearities in aerodynamic forces are ignored

Kareem, Ahsan

51

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

E-Print Network [OSTI]

A Comparison of Wind Turbine Load Statistics for Inflow Turbulence Fields based on Conventional turbine load statistics for design. There are not many published studies that have addressed the issue of such optimal space-time resolution. This study in- vestigates turbine extreme and fatigue load statistics

Manuel, Lance

52

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

SciTech Connect (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

53

Anisotropic MHD Turbulence in the Interstellar Medium and Solar Wind  

E-Print Network [OSTI]

in k-space Energy cascade rate: (k) k E(k) { Energy spectrum: = constant E(k)dk = total energy = 5;Globally isotropic 2D energy spectrum (logarithmic contours) +0 #12;Current sheet formation intense current. Bhattacharjee, K. Germaschewski S. Galtier #12;Outline · Introduction · Global anisotropy: weak MHD turbulence

Ng, Chung-Sang

54

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

SciTech Connect (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

55

Coherent structures in ion temperature gradient turbulence-zonal flow  

SciTech Connect (OSTI)

Nonlinear stationary structure formation in the coupled ion temperature gradient (ITG)-zonal flow system is investigated. The ITG turbulence is described by a wave-kinetic equation for the action density of the ITG mode, and the longer scale zonal mode is described by a dynamic equation for the m?=?n?=?0 component of the potential. Two populations of trapped and untrapped drift wave trajectories are shown to exist in a moving frame of reference. This novel effect leads to the formation of nonlinear stationary structures. It is shown that the ITG turbulence can self-consistently sustain coherent, radially propagating modulation envelope structures such as solitons, shocks, and nonlinear wave trains.

Singh, Rameswar, E-mail: rameswar.singh@lpp.polytechnique.fr [Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); Singh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Kaw, P. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); Grcan, . D. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); CMTFO and CASS, University of California, San Diego, California 92093 (United States)

2014-10-15T23:59:59.000Z

56

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

E-Print Network [OSTI]

measurements of the wind fields engulfing today's huge wind turbines. Our aim is to measure in real- time 3D velocity field, ,within the volumes that fully surround the huge wind turbines of today and tomorrow atmospheric flow that surrounds the giant wind turbines. This new knowledge we envision will accelerate

57

Solar wind turbulence from MHD to sub-ion scales: high-resolution hybrid simulations  

E-Print Network [OSTI]

We present results from a high-resolution and large-scale hybrid (fluid electrons and particle-in-cell protons) two-dimensional numerical simulation of decaying turbulence. Two distinct spectral regions (separated by a smooth break at proton scales) develop with clear power-law scaling, each one occupying about a decade in wave numbers. The simulation results exhibit simultaneously several properties of the observed solar wind fluctuations: spectral indices of the magnetic, kinetic, and residual energy spectra in the magneto-hydrodynamic (MHD) inertial range along with a flattening of the electric field spectrum, an increase in magnetic compressibility, and a strong coupling of the cascade with the density and the parallel component of the magnetic fluctuations at sub-proton scales. Our findings support the interpretation that in the solar wind large-scale MHD fluctuations naturally evolve beyond proton scales into a turbulent regime that is governed by the generalized Ohm's law.

Franci, Luca; Matteini, Lorenzo; Landi, Simone; Hellinger, Petr

2015-01-01T23:59:59.000Z

58

The slow-mode nature of compressible wave power in solar wind turbulence  

E-Print Network [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_parallel) between proton density fluctuations delta n and the field-aligned (compressible) component of the magnetic field delta B_parallel is negative and close to -1. The typical dependence of C(delta n,delta B_parallel) on the ion plasma beta_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; Chen, C H K; Salem, C S; TenBarge, J M

2011-01-01T23:59:59.000Z

59

Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum  

E-Print Network [OSTI]

Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...

Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W

2015-01-01T23:59:59.000Z

60

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

2005-08-29T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Subgrid-scale model for the temperature fluctuations in reacting hypersonic turbulent flows  

E-Print Network [OSTI]

Subgrid-scale model for the temperature fluctuations in reacting hypersonic turbulent flows M. Pino fluctuations for use in large-eddy simulations of turbulent, reacting hypersonic flows. The proposed model uses, a greater understand- ing of turbulent hypersonic flows is needed. Direct numerical simulations DNS

Martín, Pino

62

Nonlinear interaction of proton whistler with kinetic Alfvn wave to study solar wind turbulence  

SciTech Connect (OSTI)

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

Goyal, R.; Sharma, R. P. [Centre for Energy Studies, Indian Institute of Technology, Delhi-110016 (India)] [Centre for Energy Studies, Indian Institute of Technology, Delhi-110016 (India); Goldstein, M. L. [NASA Goddard Space Flight Centre, Code 673, Greenbelt, Maryland 20771 (United States)] [NASA Goddard Space Flight Centre, Code 673, Greenbelt, Maryland 20771 (United States); Dwivedi, N. K. [Austrian Academy of Sciences, Space Research Institute, Schmiedlstrasse 6, 8042 Graz (Austria)] [Austrian Academy of Sciences, Space Research Institute, Schmiedlstrasse 6, 8042 Graz (Austria)

2013-12-15T23:59:59.000Z

63

High-Temperature Motor Windings for Downhole Pumps Used in Geothermal...  

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

High-Temperature Motor Windings for Downhole Pumps Used in Geothermal Energy Production High-Temperature Motor Windings for Downhole Pumps Used in Geothermal Energy Production...

64

Ion temperature gradient driven turbulence with strong trapped ion resonance  

SciTech Connect (OSTI)

A theory to describe basic characterization of ion temperature gradient driven turbulence with strong trapped ion resonance is presented. The role of trapped ion granulations, clusters of trapped ions correlated by precession resonance, is the focus. Microscopically, the presence of trapped ion granulations leads to a sharp (logarithmic) divergence of two point phase space density correlation at small scales. Macroscopically, trapped ion granulations excite potential fluctuations that do not satisfy dispersion relation and so broaden frequency spectrum. The line width from emission due only to trapped ion granulations is calculated. The result shows that the line width depends on ion free energy and electron dissipation, which implies that non-adiabatic electrons are essential to recover non-trivial dynamics of trapped ion granulations. Relevant testable predictions are summarized.

Kosuga, Y., E-mail: kosuga@riam.kyushu-u.ac.jp [Institute for Advanced Study, Kyushu University, Fukuoka (Japan); Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan); Itoh, S.-I. [Research Center for Plasma Turbulence, Kyushu University, Fukuoka (Japan); Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan); Diamond, P. H. [CASS and CMTFO, University of California at San Diego, La Jolla, California 92093 (United States); WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon (Korea, Republic of); Itoh, K. [National Institute for Fusion Science, Gifu (Japan); Research Center for Plasma Turbulence, Kyushu University, Fukuoka (Japan); Lesur, M. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan)

2014-10-15T23:59:59.000Z

65

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

E-Print Network [OSTI]

We study the evolution of turbulence in the solar wind by solving numerically the full 3D magneto-hydrodynamic (MHD) equations embedded in a radial mean wind. The corresponding equations (expanding box model or EBM) have been considered earlier but never integrated in 3D simulations. Here, we follow the development of turbulence from 0.2 AU up to about 1.5 AU. Starting with isotropic spectra scaling as $k^{-1}$, we observe a steepening toward a $k^{-5/3}$ scaling in the middle of the wavenumber range and formation of spectral anisotropies. The advection of a plasma volume by the expanding solar wind causes a non-trivial stretching of the volume in directions transverse to radial and the selective decay of the components of velocity and magnetic fluctuations. These two effects combine to yield the following results. (i) Spectral anisotropy: gyrotropy is broken, and the radial wavevectors have most of the power. (ii) Coherent structures: radial streams emerge that resemble the observed microjets. (iii) Energy s...

Dong, Yue; Grappin, Roland

2014-01-01T23:59:59.000Z

66

Turbulence in the solar wind: spectra from Voyager 2 data at 5 AU  

E-Print Network [OSTI]

The solar wind spectral properties are far from uniformity and evolve with the increasing distance from the sun. Most of the available spectra of solar wind turbulence were computed at 1 astronomical unit, while accurate spectra on wide frequency ranges at larger distances are still few. In this paper we consider solar wind spectra derived from the data recorded by the Voyager 2 mission during 1979 at about 5 AU from the sun. Voyager 2 data are an incomplete time series with a voids/signal ratio that typically increases as the spacecraft moves away from the sun (45% missing data in 1979), making the analysis challenging. In order to estimate the uncertainty of the spectral slopes, different methods are tested on synthetic turbulence signals with the same gap distribution as V2 data. Spectra of all variables show a power law scaling with exponents between -2.1 and -1.1, depending on frequency subranges. PDFs and correlations indicate that the flow has a significant intermittency.

Fraternale, F; Iovieno, M; Opher, M; Richardson, J D; Tordella, D

2015-01-01T23:59:59.000Z

67

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

2009-12-25T23:59:59.000Z

68

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

SciTech Connect (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

69

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

70

Inertial-Range Reconnection in Magnetohydrodynamic Turbulence and in the Solar Wind  

E-Print Network [OSTI]

In situ spacecraft data on the solar wind show events identified as magnetic reconnection with outflows and apparent "`$X$-lines" $10^{3-4}$ times ion scales. To understand the role of turbulence at these scales, we make a case study of an inertial-range reconnection event in a magnetohydrodynamic (MHD) simulation. We observe stochastic wandering of field-lines in space, breakdown of standard magnetic flux-freezing due to Richardson dispersion, and a broadened reconnection zone containing many current sheets. The coarse-grain magnetic geometry is like large-scale reconnection in the solar wind, however, with a hyperbolic flux-tube or "$X$-line" extending over integral length-scales.

Lalescu, Cristian C; Eyink, Gregory L; Drivas, Theodore D; Vishniac, Ethan T; Lazarian, Alexander

2015-01-01T23:59:59.000Z

71

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

E-Print Network [OSTI]

versus lapse rate of temperature for obser- vations of CAT (rms-r a 0. 85 mps) over the 250-m, 500-m, and 1000-m layers. . . . . . . . . . . . 31 Profile of wind speed measured by the FPS-16 radar/Jimsphere system over Cape Kennedy, Florida. LIST... profiles to mean meteorological para- meters. Detailed wind profiles, measured by the FPS-16 radar/ Jimsphere system, and rawinsonde profiles are the main sources of data. The Jimsphere balloon was developed to furnish a wind sensor that would give...

Blackburn, James Harvey

2012-06-07T23:59:59.000Z

72

Surface Temperature and Surface-Layer Turbulence in a Convective Boundary Layer  

E-Print Network [OSTI]

The vertical gradient of horizontal wind-speed was estimateda larger vertical gradient of horizontal wind-speed in thewind speed, direction, temperature, humidity up to 20 km with a vertical

Garai, Anirban; Pardyjak, Eric; Steeneveld, Gert-Jan; Kleissl, Jan

2013-01-01T23:59:59.000Z

73

The curvature of the wind profile as a factor in the formation of clear-air turbulence  

E-Print Network [OSTI]

&N University; Chairman of Advisory Committee: Dr. James R. Scoggins This study concerns the importance of the curvature of the wind profile to the amplitude of mountain waves. Mechanisms favor- able for clear-air turbulence (CAT) are discussed in relation... to such wave motions. Relationships between CAT encountered in the stratosphere by an XB-70 aircraft over mountain-wave areas and the curvature of the wind profile in the troposphere, are studied. Expected mountain- wave areas are defined from topographical...

Possiel, Norman Charles

1974-01-01T23:59:59.000Z

74

Characterization of the Turbulent Magnetic Integral Length in the Solar Wind: From 0.3 to 5 Astronomical Units  

E-Print Network [OSTI]

The solar wind is a structured and complex system, in which the fields vary strongly over a wide range of spatial and temporal scales. As an example, the turbulent activity in the wind affects the evolution in the heliosphere of the integral turbulent scale or correlation length [{\\lambda}], usually associated with the breakpoint in the turbulent-energy spectrum that separates the inertial range from the injection range. This large variability of the fields demands a statistical description of the solar wind. In this work, we study the probability distribution function (PDF) of the magnetic autocorrelation lengths observed in the solar wind at different distances from the Sun. We use observations from Helios, ACE, and Ulysses spacecraft. We distinguish between the usual solar wind and one of its transient components (Interplanetary Coronal Mass Ejections, ICMEs), and study also solar wind samples with low and high proton beta [\\beta_p ]. We find that in the last 3 regimes the PDF of {\\lambda} is a log-normal ...

Ruiz, M E; Matthaeus, W H; Weygand, J M

2014-01-01T23:59:59.000Z

75

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-inertial energy available for ocean mixing at depth is, at most, 0.1 TW. This confirms a recent suggestion energy source for the diapycnal mixing in the ocean required to maintain the meridional over- turning

Miami, University of

76

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

77

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

78

Predicting hottest spot temperatures in ventilated dry type transformer windings  

SciTech Connect (OSTI)

Test data indicates that hottest spot allowances used in IEEE standards for ventilated dry type transformers above 500 kVA are too low. A mathematical model to predict hottest spot temperature rises in ventilated dry type transformers was developed. Data from six layer type test windings and a 2500 kva prototype was used to refine the model. A correlation for the local heat transfer coefficient in the cooling ducts was developed. The model was used to study the effect of various parameters on the ratio of hottest spot to average winding temperature rise. The number of conductor layers, insulation thickness, and conductor strand size were found to have only a minor effect on the ratio. Winding height was found to be the main parameter influencing the ratio of hottest spot to average winding temperature rise. The study based on the mathematical model confirmed previous conclusions based on test data that the hottest spot allowances used in IEEE standards for ventilated dry type transformers above 500 kVA should be revised.

Pierce, L.W. (General Electric Co., Rome, GA (United States))

1994-04-01T23:59:59.000Z

79

Solar turbulence in earth's global and regional temperature anomalies Nicola Scafetta,1,2  

E-Print Network [OSTI]

Solar turbulence in earth's global and regional temperature anomalies Nicola Scafetta,1,2 Paolo a study of the influence of solar activity on the earth's temperature. In particular, we focus on the repercussion of the fluctuations of the solar irradiance on the temperature of the Northern and Southern

Scafetta, Nicola

80

Gyrokinetic and Gyrofluid Models for Zonal Flow Dynamics in Ion and Electron Temperature Gradient Turbulence  

SciTech Connect (OSTI)

Collisionless time evolution of zonal flows in ion and electron temperature gradient turbulence in toroidal plasmas is investigated. The responses of the zonal-flow potential to the initial perturbation and to the turbulence source are determined from the gyrokinetic equations combined with the Poisson equation, A novel gyrofluid model is presented, which properly describes the zonal-flow time evolution and reproduces the same residual zonal-flow levels as predicted by the gyrokinetic model.

Sugama, H.; Watanabe, T.-H. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan); Graduate University for Advanced Studies, Toki, Gifu, 509-5292 (Japan); Ferrando i Margalet, S. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan)

2006-11-30T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Ris-R-1188(EN) Turbulence and turbulence-  

E-Print Network [OSTI]

Ris-R-1188(EN) Turbulence and turbulence- generated structural loading in wind turbine clusters to ensure sufficient structural sustainability of the wind turbines exposed to "wind farm flow turbulence intensity inside the wind farm and direct-wake turbulence intensity are being devised and a method

82

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

SciTech Connect (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

83

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

84

Aspects of the theory of incompressible MHD turbulence with cross-helicity and applications to the solar wind  

SciTech Connect (OSTI)

Solar wind observations have shown that the normalized cross-helicity {sigma}{sub c}, the ratio of the cross-helicity spectrum to the energy spectrum, is approximately constant, independent of wavenumber, throughout the inertial range. This means that the correlation between velocity and magnetic field fluctuations is the same at every scale, that the ratio of the two Elsasser energies (w{sup +}/w{sup -}){sup 2} is the same at every scale, and that the ratio of the energy cascade times of the two Elsasser energies {tau}{sup +}/{tau}{sup -} is the same at every scale. In the case when the magnetic Prandtl number is unity, it can be shown from the equations of incompressible MHD that if {sigma}{sub c} is a constant, then the cascade times of the two Elsasser energies are equal so that {tau}{sup +}/{tau}{sup -} = 1. This is an important constraint for turbulence theories. Using this result, the Goldreich and Sridhar theory and the Boldyrev theory are generalized to MHD turbulence with nonvanishing cross-helicity in such a way that the scaling laws of the original two theories are unchanged. The derivation and some of the important properties of these more general theories shall be presented. Solar wind measurements in support of these theoretical models will also be discussed. For example, new solar wind measurements of the total energy spectrum (kinetic plus magnetic) show that the power-law exponent is closer to 3/2 than 5/3, consistent with simulations of 3D incompressible MHD turbulence with a strong mean meagnetic field that show a 3/2 scaling. For highly Alfvenic, high cross-helicity solar wind turbulence, new measurements presented her show that the average spectral index is 1.540 {+-} 0.033.

Podesta, John J [Los Alamos National Laboratory

2010-12-03T23:59:59.000Z

85

Diurnal and seasonal variations of wind farm impacts on land surface temperature over western Texas  

E-Print Network [OSTI]

Diurnal and seasonal variations of wind farm impacts on land surface temperature over western Texas for the period of 20032011 over a region in West-Central Texas, where four of the world's largest wind farms by comparing the LST changes between wind farm pixels (WFPs) and nearby non wind farm pixels (NNWFPs) using

Zhou, Liming

86

Two techniques for forecasting clear air turbulence  

E-Print Network [OSTI]

for the height of the 200- and )00-mb pressure surfaces associated with nonturbulent and turbulent cases . . . . . . o. . . . . o o ~ o ~ . ~ . 17 4. Empirical frequency distributions for the temperature of the 200- and 300-mb pressure surfaces associated... with nonturbulent and turbulent areas. . . . . . ~ . . . . . ~ . ~ ~ Empirical frequency distributions of the zonal wind component on the 200- and 300-mb press- ure surfaces associated with nonturbulent and turbulent areas . . . . . . . . . . . . ~ ~ 20...

Arbeiter, Randolph George

2012-06-07T23:59:59.000Z

87

Role of ion temperature on scrape-off layer plasma turbulence  

SciTech Connect (OSTI)

Turbulence in Scrape-off layer (SOL) of tokamak plasma has been studied numerically using interchange modes with the help of electron continuity, quasineutrality, and ion energy equations. Electron temperature is assumed uniform. We have studied dynamics of seeded plasma blob and plasma turbulence to identify the role of ion temperature and its gradient. The ion temperature elongates the blob poloidally and reduces its radial velocity. Initial dipole nature of the plasma blob potential breaks and generates few more dipoles during its propagation in the SOL. Plasma turbulence simulation shows poloidally elongated density and ion temperature structures that are similar to the seeded blob simulation studies. Fluctuations of the density and ion temperature have been presented as function of scale lengths of the density and ion temperature. Reduction of the SOL width and increase of radial electric field have been measured in the presence of the ion temperature. Particle and energy transports have been also presented as the function of the density and ion temperature scale lengths.

Bisai, N.; Kaw, P. K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2013-04-15T23:59:59.000Z

88

On prediction of wind-borne plumes with simple models of turbulent transport  

E-Print Network [OSTI]

of x, and the vertical wind speed of gas above ground wass x 10 Vertical gas velocity, horizontal wind speed = 1 m/ss x 10 Vertical gas velocity, horizontal wind speed = 5 m/s

Schwarz, Katherine; Patzek, Tad; Silin, Dmitriy

2008-01-01T23:59:59.000Z

89

Fine-Scale Zonal Flow Suppression of Electron Temperature Gradient Turbulence  

SciTech Connect (OSTI)

It is found in collisionless Electron Temperature Gradient (ETG) turbulence simulations that, while zonal flows are weak at early times, the zonal flows continue to grow algebraically (proportional to time). These fine-scale zonal flows have a radial wave number such that kr{rho}i > 1 and kr{rho}e < 1. Eventually, the zonal flows grow to a level that suppresses the turbulence due to ExB shearing. The final electron energy flux is found to be relatively low. These conclusions are based on particle convergence studies with adiabatic ion electrostatic flux-tube gyrokinetic {delta}f particle simulations run for long times. The Rosenbluth-Hinton random walk mechanism is given as an explanation for the long time build up of the zonal flow in ETG turbulence and it is shown that the generation is (k perpendicular {rho}e)2 smaller than for isomorphic Ion Temperature Gradient (ITG) problem. This mechanism for zonal flow generation here is different than the modulational instability mechanism for ITG turbulence. These results are important because previous results indicated zonal flows were unimportant for ETG turbulence. Weak collisional damping of the zonal flow is also shown to be a n important effect.

Parker, S. E.; Kohut, J. J.; Chen, Y. [Center for Integrated Plasma Studies, University of Colorado, Boulder, C0 (United States); Lin, Z. [University of Californian, Irvine, CA (United States); Hinton, F. L. [Hinton Associates, Escondido, CA (United States); Lee, W. W. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States)

2006-11-30T23:59:59.000Z

90

Gyrokinetic-Vlasov simulations of the ion temperature gradient turbulence in tokamak and helical systems  

SciTech Connect (OSTI)

Recent progress of the gyrokinetic-Vlasov simulations on the ion temperature gradient (ITG) turbulence in tokamak and helical systems is reported, where the entropy balance is checked as a reference for the numerical accuracy. The tokamak ITG turbulence simulation carried out on the Earth Simulator clearly captures a nonlinear generation process of zonal flows. The tera-flops and tera-bytes scale simulation is also applied to a helical system with the same poloidal and toroidal periodicities of L = 2 and M = 10 as in the Large Helical Device.

Watanabe, T.-H.; Sugama, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Graduate University for Advanced Studies (Sokendai), Toki, Gifu 509-5292 (Japan); Ferrando i Margalet, S. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

2006-11-30T23:59:59.000Z

91

What is Wind Chill Temperature? It is the temperature it "feels like" outside and is based on the rate of heat loss  

E-Print Network [OSTI]

What is Wind Chill Temperature? It is the temperature it "feels like" outside and is based on the rate of heat loss from exposed skin caused by the effects of wind and cold. As the wind increases, the body is cooled at a faster rate causing the skin temperature to drop. Wind Chill does not impact

92

High-Temperature Motor Windings for Downhole Pumps Used in Geothermal Energy Production  

Broader source: Energy.gov [DOE]

Project objective: Develop and demonstrate high-temperature ESP motor windings for use in Enhanced Geothermal Systems and operation at 300?C.

93

High-Temperature Motor Windings for Downhole Pumps Used in Geothermal...  

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

and Other Harsh Environments High-Temperature Motor Windings for Downhole Pumps Used in Geothermal Energy Production Matthew Hooker Composite Technology Development, Inc....

94

Coherent structures, intermittent turbulence, and dissipation in high-temperature plasmas  

SciTech Connect (OSTI)

An unsolved problem in plasma turbulence is how energy is dissipated at small scales. Particle collisions are too infrequent in hot plasmas to provide the necessary dissipation. Simulations either treat the fluid scales and impose an ad hoc form of dissipation (e.g., resistivity) or consider dissipation arising from resonant damping of small amplitude disturbances where damping rates are found to be comparable to that predicted from linear theory. Here, we report kinetic simulations that span the macroscopic fluid scales down to the motion of electrons. We find that turbulent cascade leads to generation of coherent structures in the form of current sheets that steepen to electron scales, triggering strong localized heating of the plasma. The dominant heating mechanism is due to parallel electric fields associated with the current sheets, leading to anisotropic electron and ion distributions which can be measured with NASA's upcoming Magnetospheric Multiscale mission. The motion of coherent structures also generates waves that are emitted into the ambient plasma in form of highly oblique compressional and shear Alfven modes. In 3D, modes propagating at other angles can also be generated. This indicates that intermittent plasma turbulence will in general consist of both coherent structures and waves. However, the current sheet heating is found to be locally several orders of magnitude more efficient than wave damping and is sufficient to explain the observed heating rates in the solar wind.

Karimabadi, H.; Roytershteyn, V. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093 (United States); Wan, M.; Matthaeus, W. H.; Wu, P.; Shay, M. [University of Delaware, Department of Physics and Astronomy, Newark, Delaware 19716 (United States); Daughton, W.; Nakamura, T. K. M. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Loring, B. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Borovsky, J. [Space Science Institute, Boulder, Colorado 80301 (United States); Leonardis, E.; Chapman, S. C. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, CV4 7AL (United Kingdom)

2013-01-15T23:59:59.000Z

95

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

E-Print Network [OSTI]

turbines become taller wind energy assessment and also turbine control require knowledge of the detailed calibrated cup anemometers in tall met-towers, wind data from remote-sensing instrumentation, such as SODARS, in particular for use in connection with power curve reference and wind turbine certification purposes. However

96

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

97

Wind observations of extreme ion temperature anisotropies in the D. Clack,1,2  

E-Print Network [OSTI]

Wind observations of extreme ion temperature anisotropies in the lunar wake D. Clack,1,2 J. C directional changes show that the wake geometry is dependent upon the prevailing magnetic field orientation (2004), Wind observations of extreme ion temperature anisotropies in the lunar wake, Geophys. Res. Lett

Richardson, John

98

How to use CFD for Wind in Terrain ... real-life experience!  

E-Print Network [OSTI]

: Turbulence modelling / numerical methods Inclusion of wind turbine wake Temperature stratification 2 study 3. Construction and operation 4. Wind turbine breakdown! 5. Wind measurements / CFD simulations1 How to use CFD for Wind in Terrain ... real-life experience! CFD day at Suzlon, October 2007 A

99

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

E-Print Network [OSTI]

. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays-tunnel configuration of the Swarthmore Spheromak Experiment (SSX) [16,17] explores this possible relationship between indices. The scan is conducted on the wind-tunnel configuration of the Swarthmore Spheromak Experiment

Brown, Michael R.

100

Heating of the Solar Wind Beyond 1 AU by Turbulent Dissipation  

E-Print Network [OSTI]

19716, USA 2Department of Mathematics, University College London, UK Abstract The deposition of energy(comp) = Cshear(comp) U r Z2 (1) where Z2 = hv2 +b2i is the energy density, U is the solar wind speed, and Cshear in the solar wind frame would yield a spherical distribution (solid curve). The di erence in kinetic energy

Oughton, Sean

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Wasted Wind  

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

why turbulent airflows are causing power losses and turbine failures in America's wind farms-and what to do about it April 1, 2014 Wasted Wind This aerial photo of Denmark's Horns...

102

Brushless exciters using a high temperature superconducting field winding  

DOE Patents [OSTI]

A brushless exciter for a synchronous generator or motor generally includes a stator and a rotor rotatably disposed within the stator. The rotor has a field winding and a voltage rectifying bridge circuit connected in parallel to the field winding. A plurality of firing circuits are connected the voltage rectifying bridge circuit. The firing circuit is configured to fire a signal at an angle of less than 90.degree. or at an angle greater than 90.degree.. The voltage rectifying bridge circuit rectifies the AC voltage to excite or de-excite the field winding.

Garces, Luis Jose (Schenectady, NY); Delmerico, Robert William (Clifton Park, NY); Jansen, Patrick Lee (Scotia, NY); Parslow, John Harold (Scotia, NY); Sanderson, Harold Copeland (Tribes Hill, NY); Sinha, Gautam (Chesterfield, MO)

2008-03-18T23:59:59.000Z

103

Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise spectroscopy  

E-Print Network [OSTI]

Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise of the plasma thermal noise analysis for the Solar Orbiter, in order to get accurate measurements of the total of their small mass and therefore large thermal speed, the solar wind electrons are expected to play a major role

California at Berkeley, University of

104

Comparison of analytical models for zonal flow generation in ion-temperature-gradient mode turbulence  

SciTech Connect (OSTI)

During the past years the understanding of the multi scale interaction problems have increased significantly. However, at present there exists a flora of different analytical models for investigating multi scale interactions and hardly any specific comparisons have been performed among these models. In this work two different models for the generation of zonal flows from ion-temperature-gradient (ITG) background turbulence are discussed and compared. The methods used are the coherent mode coupling model and the wave kinetic equation model (WKE). It is shown that the two models give qualitatively the same results even though the assumption on the spectral difference is used in the (WKE) approach.

Anderson, J.; Miki, K.; Uzawa, K.; Li, J.; Kishimoto, Y. [Dept. Fundamental Energy Science, School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 (Japan)

2006-11-30T23:59:59.000Z

105

TEMPERATURE AND MOISTURE EFFECTS ON COMPOSITE MATERIALS FOR WIND TURBINE BLADES  

E-Print Network [OSTI]

TEMPERATURE AND MOISTURE EFFECTS ON COMPOSITE MATERIALS FOR WIND TURBINE BLADES by Mei Li A thesis graduate students in the composite materials group for their help and kindness. Finally, thanks to my dear

106

Generation of large-scale winds in horizontally anisotropic convection  

E-Print Network [OSTI]

We simulate three-dimensional, horizontally periodic Rayleigh-B\\'enard convection between free-slip horizontal plates, rotating about a horizontal axis. When both the temperature difference between the plates and the rotation rate are sufficiently large, a strong horizontal wind is generated that is perpendicular to both the rotation vector and the gravity vector. The wind is turbulent, large-scale, and vertically sheared. Horizontal anisotropy, engendered here by rotation, appears necessary for such wind generation. Most of the kinetic energy of the flow resides in the wind, and the vertical turbulent heat flux is much lower on average than when there is no wind.

von Hardenberg, J; Provenzale, A; Spiegel, E A

2015-01-01T23:59:59.000Z

107

Turbulence and turbulent mixing in natural fluids  

E-Print Network [OSTI]

Turbulence and turbulent mixing in natural fluids begins with big bang turbulence powered by spinning combustible combinations of Planck particles and Planck antiparticles. Particle prograde accretion on a spinning pair releases 42% of the particle rest mass energy to produce more fuel for turbulent combustion. Negative viscosity and negative turbulence stresses work against gravity, creating mass-energy and space-time from the vacuum. Turbulence mixes cooling temperatures until a quark-gluon strong-force SF freeze-out. Gluon-viscosity anti-gravity ({\\Lambda}SF) exponentially inflates the fireball to preserve big bang turbulence information at scales larger than ct as the first fossil turbulence. Cosmic microwave background CMB temperature anisotropies show big bang turbulence fossils along with fossils of weak plasma turbulence triggered (10^12 s) as plasma viscous forces permit gravitational fragmentation on supercluster to galaxy mass scales (10^13 s). Turbulent morphologies and viscous-turbulent lengths a...

Gibson, Carl H

2010-01-01T23:59:59.000Z

108

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

SciTech Connect (OSTI)

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

Hollweg, Joseph V.; Chandran, Benjamin D. G. [Space Science Center, Morse Hall, University of New Hampshire, Durham, NH 03824 (United States); Kaghashvili, Edisher Kh., E-mail: joe.hollweg@unh.edu, E-mail: ekaghash@aer.com, E-mail: benjamin.chandran@unh.edu [Atmospheric and Environmental Research, A Verisk Analytics Company, 131 Hartwell Avenue, Lexington, MA 02421 (United States)

2013-06-01T23:59:59.000Z

109

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

SciTech Connect (OSTI)

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

110

A study of self organized criticality in ion temperature gradient mode driven gyrokinetic turbulence  

SciTech Connect (OSTI)

An investigation on the characteristics of self organized criticality (Soc) in ITG mode driven turbulence is made, with the use of various statistical tools (histograms, power spectra, Hurst exponents estimated with the rescaled range analysis, and the structure function method). For this purpose, local non-linear gyrokinetic simulations of the cyclone base case scenario are performed with the GENE software package. Although most authors concentrate on global simulations, which seem to be a better choice for such an investigation, we use local simulations in an attempt to study the locally underlying mechanisms of Soc. We also study the structural properties of radially extended structures, with several tools (fractal dimension estimate, cluster analysis, and two dimensional autocorrelation function), in order to explore whether they can be characterized as avalanches. We find that, for large enough driving temperature gradients, the local simulations exhibit most of the features of Soc, with the exception of the probability distribution of observables, which show a tail, yet they are not of power-law form. The radial structures have the same radial extent at all temperature gradients examined; radial motion (transport) though appears only at large temperature gradients, in which case the radial structures can be interpreted as avalanches.

Mavridis, M.; Isliker, H.; Vlahos, L. [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Grler, T.; Jenko, F.; Told, D. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany)

2014-10-15T23:59:59.000Z

111

Q&A on "Impacts of Wind Farms on Land Surface Temperature" Published by Nature Climate Change on April 29, 2012  

E-Print Network [OSTI]

1 Q&A on "Impacts of Wind Farms on Land Surface Temperature" Published by Nature Climate Change? This study presents the first observational evidence of wind farm impacts on land surface temperature downwind of wind farms. Why do the operating wind turbines warm nighttime temperature? This warming effect

Zhou, Liming

112

Observations of turbulent fluxes and turbulence dynamics in the ocean surface boundary layer  

E-Print Network [OSTI]

This study presents observations of turbulence dynamics made during the low winds portion of the Coupled Boundary Layers and Air-Sea Transfer experiment (CBLAST-Low). Observations were made of turbulent fluxes, turbulent ...

Gerbi, Gregory Peter

2008-01-01T23:59:59.000Z

113

STOCHASTIC HEATING, DIFFERENTIAL FLOW, AND THE ALPHA-TO-PROTON TEMPERATURE RATIO IN THE SOLAR WIND  

SciTech Connect (OSTI)

We extend previous theories of stochastic ion heating to account for the motion of ions along the magnetic field B . We derive an analytic expression for the temperature ratio T{sub i}/T{sub p} in the solar wind assuming that stochastic heating is the dominant ion heating mechanism, where T{sub i} is the perpendicular temperature of species i and T{sub p} is the perpendicular proton temperature. This expression describes how T{sub i}/T{sub p} depends upon U{sub i} and ?{sub ?p}, where U{sub i} is the average velocity along B of species i in the proton frame and ?{sub ?p} is the ratio of the parallel proton pressure to the magnetic pressure, which we take to be ?< 1. We compare our model with previously published measurements of alpha particles and protons from the Wind spacecraft. We find that stochastic heating offers a promising explanation for the dependence of T{sub ?}/T{sub p} on U{sub ?} and ?{sub ?p} when the fractional cross helicity and Alfvn ratio at the proton-gyroradius scale have values that are broadly consistent with solar-wind measurements. We also predict how the temperatures of other ion species depend on their drift speeds.

Chandran, B. D. G.; Verscharen, D.; Isenberg, P. A.; Bourouaine, S. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Quataert, E. [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, The University of California, Berkeley, CA 94720 (United States); Kasper, J. C., E-mail: benjamin.chandran@unh.edu, E-mail: s.bourouaine@unh.edu, E-mail: phil.isenberg@unh.edu, E-mail: daniel.verscharen@unh.edu, E-mail: eliot@astro.berkeley.edu, E-mail: jkasper@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2013-10-10T23:59:59.000Z

114

Winding Transitions at Finite Energy and Temperature: An O(3) Model  

E-Print Network [OSTI]

Winding number transitions in the two dimensional softly broken O(3) nonlinear sigma model are studied at finite energy and temperature. New periodic instanton solutions which dominate the semiclassical transition amplitudes are found analytically at low energies, and numerically for all energies up to the sphaleron scale. The Euclidean period beta of these finite energy instantons increases with energy, contrary to the behavior found in the abelian Higgs model or simple one dimensional systems. This results in a sharp crossover from instanton dominated tunneling to sphaleron dominated thermal activation at a certain critical temperature. Since this behavior is traceable to the soft breaking of conformal invariance by the mass term in the sigma model, semiclassical winding number transition amplitudes in the electroweak theory in 3+1 dimensions should exhibit a similar sharp crossover. We argue that this is indeed the case in the standard model for M_H < 4 M_W.

Salman Habib; Emil Mottola; Peter Tinyakov

1996-08-14T23:59:59.000Z

115

Tracing solar wind plasma entry into the magnetosphere1 using ion-to-electron temperature ratio2  

E-Print Network [OSTI]

solar wind conditions, i.e., high MA (> 6),54 energy conversion at the bow shock leads to high ion-to-551 Tracing solar wind plasma entry into the magnetosphere1 using ion-to-electron temperature ratio2 Department of Physics, La Trobe University, Victoria, Australia18 11 Geophysik & extraterrestrische physik

Paris-Sud XI, Université de

116

Examination of Errors in Near-Surface Temperature and Wind from WRF Numerical Simulations in Regions of Complex Terrain  

E-Print Network [OSTI]

-surface atmospheric conditions are very important in many applications such as wind energy, agriculture, aviationExamination of Errors in Near-Surface Temperature and Wind from WRF Numerical Simulations of Utah, Salt Lake City, Utah XUEBO ZHANG Computational Engineering and Science, University of Utah, Salt

Pu, Zhaoxia

117

Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines  

SciTech Connect (OSTI)

This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes. Based on the cost and performance data supplied by AMSC, HTSDD technology has good potential to compete successfully as an alternative technology to PMDD and geared technology turbines in the multi megawatt classes. In addition, data suggests the economics of HTSDD turbines improve with increasing size, although several uncertainties remain for all machines in the 6 to 10 MW class.

Maples, B.; Hand, M.; Musial, W.

2010-10-01T23:59:59.000Z

118

High-Temperature Motor Windings for Downhole Pumps Used in Geothermal Energy Production  

SciTech Connect (OSTI)

The development of highly reliable downhole equipment is an essential element in enabling the widespread utilization of Enhanced Geothermal Systems (EGS). The downhole equipment used in these systems will be required to operate at high voltages and temperatures on the order of 200 to 250C (and eventually to 300?C). These conditions exceed the practical operating ranges of currently available thermoplastic wire insulations, and thus limit the operating lifetime of tools such as Electric Submersible Pumps (ESPs). In this work, high-temperature insulations based on composite materials were developed and demonstrated. The products of this work were found to exhibit electrical resistivities and dielectric breakdown strengths that PEEK at temperatures above 250C. In addition, sub-scale motor windings were fabricated and tested to validate the performance of this technology

Hooker, Matthew; Hazelton, Craig; Kano, Kimi

2010-12-31T23:59:59.000Z

119

System and method for monitoring and controlling stator winding temperature in a de-energized AC motor  

DOE Patents [OSTI]

A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

Lu, Bin (Kenosha, WI); Luebke, Charles John (Sussex, WI); Habetler, Thomas G. (Snellville, GA); Zhang, Pinjia (Atlanta, GA); Becker, Scott K. (Oak Creek, WI)

2011-12-27T23:59:59.000Z

120

LIMITS ON ALPHA PARTICLE TEMPERATURE ANISOTROPY AND DIFFERENTIAL FLOW FROM KINETIC INSTABILITIES: SOLAR WIND OBSERVATIONS  

SciTech Connect (OSTI)

Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure and anisotropy driven instabilities such as the Alfvn/ion-cyclotron (A/IC) and fast-magnetosonic/whistler (FM/W) instabilities. In this Letter, we use a long period of in situ measurements provided by the Wind spacecraft's Faraday cups to investigate the combined constraint on the alpha proton differential flow velocity and the alpha particle temperature anisotropy due to A/IC and FM/W instabilities. We show that the majority of the data are constrained to lie within the region of parameter space in which A/IC and FM/W waves are either stable or have extremely low growth rates. In the minority of observed cases in which the growth rate of the A/IC (FM/W) instability is comparatively large, we find relatively higher values of T {sub ?}/T {sub p} (T {sub ??}/T {sub ?p}) when the alpha proton differential flow velocity is small, where T {sub ?} and T {sub p} (T {sub ??} and T {sub ?p}) are the perpendicular (parallel) temperatures of alpha particles and protons. We conjecture that this observed feature might arise from preferential alpha particle heating which can drive the alpha particles beyond the instability thresholds.

Bourouaine, Sofiane; Verscharen, Daniel; Chandran, Benjamin D. G. [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)] [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Maruca, Bennett A. [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States)] [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States); Kasper, Justin C., E-mail: s.bourouaine@unh.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2013-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Ultra-fast charge exchange spectroscopy for turbulent ion temperature fluctuation measurements on the DIII-D tokamak (invited)  

SciTech Connect (OSTI)

A novel two-channel, high throughput, high efficiency spectrometer system has been developed to measure impurity ion temperature and toroidal velocity fluctuations associated with long-wavelength turbulence and other plasma instabilities. The spectrometer observes the emission of the n= 8-7 hydrogenic transition of C{sup +5} ions ({lambda}{sub air}= 529.06 nm) resulting from charge exchange reactions between deuterium heating beams and intrinsic carbon. Novel features include a large, prism-coupled high-dispersion, volume-phase-holographic transmission grating and high-quantum efficiency, high-gain, low-noise avalanche photodiode detectors that sample emission at 1 MHz. This new diagnostic offers an order-of-magnitude increase in sensitivity compared to earlier ion thermal turbulence measurements. Increased sensitivity is crucial for obtaining enough photon statistics from plasmas with much less impurity content. The irreducible noise floor set by photon statistics sets the ultimate sensitivity to plasma fluctuations. Based on the measured photon flux levels for the entire spectral line, photon noise levels for T(tilde sign){sub i}/T{sub i} and V(tilde sign){sub i}/V{sub i} of {approx}1% are expected, while statistical averaging over long data records enables reduction in the detectable plasma fluctuation levels to values less than that. Broadband ion temperature fluctuations are observed to near 200 kHz in an L-mode discharge. Cross-correlation with the local beam emission spectroscopy measurements demonstrates a strong coupling of the density and temperature fields, and enables the cross-phase measurements between density and ion temperature fluctuations.

Uzun-Kaymak, I. U.; Fonck, R. J.; McKee, G. R. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2012-10-15T23:59:59.000Z

122

ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS  

SciTech Connect (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

123

On the nonlinear stability of a quasi-two-dimensional drift kinetic model for ion temperature gradient turbulence  

E-Print Network [OSTI]

We study a quasi-two-dimensional electrostatic drift kinetic system as a model for near-marginal ion temperature gradient (ITG) driven turbulence. A proof is given of the nonlinear stability of this system under conditions of linear stability. This proof is achieved using a transformation that diagonalizes the linear dynamics and also commutes with nonlinear $E\\times B$ advection. For the case when linear instability is present, a corollary is found that forbids nonlinear energy transfer between appropriately defined sets of stable and unstable modes. It is speculated that this may explain the preservation of linear eigenmodes in nonlinear gyrokinetic simulations. Based on this property, a dimensionally reduced ($\\infty\\times\\infty \\rightarrow 1$) system is derived that may be useful for understanding dynamics around the critical gradient of Dimits.

Plunk, G G

2015-01-01T23:59:59.000Z

124

Modeling Compressed Turbulence  

SciTech Connect (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

125

Turbine Inflow Characterization at the National Wind Technology Center: Preprint  

SciTech Connect (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

126

Turbine Inflow Characterization at the National Wind Technology Center  

SciTech Connect (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

127

E-Print Network 3.0 - atmospheric turbulence Sample Search Results  

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

Summary: by dissipation of the turbulent energy and tur- bulent eddies will transport heat to different atmospheric re... ., MST radar studies of wind and turbulence in the...

128

Variation in rectal temperature, respiratory rate, and pulse rate of cattle as related to variations in solar radiation, air temperature, wind velocity, and vapor pressure  

E-Print Network [OSTI]

VARIATION IN RECTAL TEMPERATURE, RESPIRATORY RATE, AND PULSE RATE GF CATTLE AS RELATED TO VARIATIONS IN SOLAR RADIATION, AIR TEMPERATURE, WIND VELOCITY, AND VAPOR PRESSURE A Dissertation By Mohammad Fazlur Rahim Quazi Approved as to style... Dissertation By Mohammad Fazlur Rahim tyiazi Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 1955 Major Subject: Genetics ? ?4...

Quazi, Mohammad Fazlur Rahim

1955-01-01T23:59:59.000Z

129

Extreme Cold Weather Warning Recent subzero wind chill temperatures have understandably brought cold stress to a heighten  

E-Print Network [OSTI]

Extreme Cold Weather Warning Recent subzero wind chill temperatures have understandably brought for Disease Control and Prevention advise that if you are going outside in extreme cold, dress appropriately. Workers who are exposed to extreme cold or work in cold environments may be at risk of cold stress

Cantlon, Jessica F.

130

Modelling and Measurements of Power Losses and Turbulence  

E-Print Network [OSTI]

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

Pryor, Sara C.

131

Stability, Energetics, and Turbulent Transport in  

E-Print Network [OSTI]

fields" Department of Astrophysical Sciences Spring Colloquium Steve Cowley (UK Atomic Energy Authority of solar-wind turbulence" Chris Chen (UC Berkeley) 2:40pm "Energy spectra in MHD turbulenceStability, Energetics, and Turbulent Transport in Astrophysical, Fusion, and Solar Plasmas 8

Torquato, Salvatore

132

Perpendicular ion acceleration in whistler turbulence  

SciTech Connect (OSTI)

Whistler turbulence is an important contributor to solar wind turbulence dissipation. This turbulence contains obliquely propagating whistler waves at electron scales, and these waves have electrostatic components perpendicular to the mean magnetic field. In this paper, a full kinetic, two-dimensional particle-in-cell simulation shows that whistler turbulence can accelerate ions in the direction perpendicular to the mean magnetic field. When the ions pass through wave-particle resonances region in the phase space during their cyclotron motion, the ions are effectively accelerated in the perpendicular direction. The simulation results suggest that whistler turbulence contributes to the perpendicular heating of ions observed in the solar wind.

Saito, S. [Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8601 (Japan)] [Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8601 (Japan); Nariyuki, Y. [Faculty of Human Development, University of Toyama, 3190, Toyama 930-8555 (Japan)] [Faculty of Human Development, University of Toyama, 3190, Toyama 930-8555 (Japan)

2014-04-15T23:59:59.000Z

133

JOURNAL of GEOPHYSICAL RESEARCH, YOLo 90, NO. C3, PAGES 4907-4910, MAY 20, 1985 The Effect of Water Temperature and Synoptic Winds on the  

E-Print Network [OSTI]

Temperature and Synoptic Winds on the Development of Surface Flows Over Narrow, Elongated Water Bodies M surfacetemperature and of the large-scalesynoptic winds on the devel- opment of surfaceflows over the water created by damming of a river). In these locations, a daytime induced breeze, including its interaction

Pielke, Roger A.

134

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

SciTech Connect (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

135

A Study of Thermal Wind in the Vicinity of a Jet Stream  

E-Print Network [OSTI]

concern ourselves only with the in- strumentation of the 8-29 since it is the aircraft which collected the data for this study. -8- The observations of wind speed and direction were obtained by the APN-66, an automatic pilot-navigator which measured..., these columns may be subdivided into nine general areas; time, position, altitude, winds, temperature, humidity, clouds, turbulence and aircraft data (indicated air speed, true air speed, drift, etc. ). This study is concerned only with the time, position...

Cunningham, Newton William

2012-06-07T23:59:59.000Z

136

Probability density function treatment of turbulence/chemistry interactions during the ignition of a temperature-stratified mixture for application to HCCI engine modeling  

SciTech Connect (OSTI)

Homogeneous charge compression ignition (HCCI) engine technology promises to reduce NO{sub x} and soot emissions while achieving high thermal efficiency. Temperature and mixture stratification are regarded as effective means of controlling the start of combustion and reducing the abrupt pressure rise at high loads. Probability density function methods are currently being pursued as a viable approach to modeling the effects of turbulent mixing and mixture stratification on HCCI ignition. In this paper we present an assessment of the merits of three widely used mixing models in reproducing the moments of reactive scalars during the ignition of a lean hydrogen/air mixture ({phi}=0.1, p=41atm, and T=1070 K) under increasing temperature stratification and subject to decaying turbulence. The results from the solution of the evolution equation for a spatially homogeneous joint PDF of the reactive scalars are compared with available direct numerical simulation (DNS) data [E.R. Hawkes, R. Sankaran, P.P. Pebay, J.H. Chen, Combust. Flame 145 (1-2) (2006) 145-159]. The mixing models are found able to quantitatively reproduce the time history of the heat release rate, first and second moments of temperature, and hydroxyl radical mass fraction from the DNS results. Most importantly, the dependence of the heat release rate on the extent of the initial temperature stratification in the charge is also well captured. (author)

Bisetti, Fabrizio [246 Hesse Hall, Mailstop 1740, Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720-1740 (United States); Chen, J.-Y. [Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720-1740 (United States); Hawkes, Evatt R. [School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, NSW 2052 (Australia); Chen, Jacqueline H. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551-9051 (United States)

2008-12-15T23:59:59.000Z

137

On the relationship between temperature and wind speed in the atmospheric surface layer  

E-Print Network [OSTI]

LIBRAR& A AN m os??E " "" ON THE RELATIONSHIP BETWEEN T" MP. "RATURE AND WIND SPEED IN THE ATMOSPHERIC SURFACE LAYER A Thesis John Me Pierrard Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... logarithmically with height+ Also, the choice of a method of determination of the roughness length must be governed by an awareness of possible errors in the wind speed meas- urementso The system used to collect the data employed in this study is susceptible...

Pierrard, John Martin

2012-06-07T23:59:59.000Z

138

E-Print Network 3.0 - anisotropic magnetohydrodynamic turbulence...  

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

Physics 57 Michigan Institute for Plasma Sci- Summary: of turbulent fluc- tuations in the solar wind. While magnetohydrodynamics remains the appro- priate theory... Michigan...

139

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

E-Print Network [OSTI]

.1029/2007JD009687. 1. Introduction [2] Solar thermal tides are global-scale waves that dom- inate to conserve wave energy. When propagating into the MLT region, the horizontal wind tidal amplitude can reach with fluorescence lidar's advantages of high temporal and spatial resolution and the capability of full diurnal

140

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

E-Print Network [OSTI]

. . . . . . . . , . . . ~ . ~ INTRODUCTION BACKGROUND TO THE PROBLEM Theory of Mountain Waves Mountain Waves and Clear Air Turbulence (CAT). Page iv v vi viii The Vertical Propagation and Transfer of Energy of Mountain Waves into the Stratosphere The Influence of Wind... and Stability on Profiles of the Scorer Parameter and the Richardson Number. ANALYSES OF DATA 20 Grouping of Data 20 Aircraft 20 Meteorological 23 Analytical Results The Normal Wind Component at 700 mb The 700? to 500-mb Lapse Rate of Temperature...

Incrocci, Thomas Paul

1970-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

A Fatigue Approach to Wind Turbine Control  

E-Print Network [OSTI]

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

142

Turbulence in Astrophysical and Laboratory Plasmas  

E-Print Network [OSTI]

MIPSE, Univ of Michigan September 15, 2010 #12;Contributing Colleagues Steve Cowley (UKAEA & Imperial-principles modeling · Identification of Alfvenic solar wind turbulence · Conclusion #12;Kinetic theory when (or ) f

Shyy, Wei

143

PUBLISHED ONLINE: 29 APRIL 2012 | DOI: 10.1038/NCLIMATE1505 Impacts of wind farms on land surface temperature  

E-Print Network [OSTI]

LETTERS PUBLISHED ONLINE: 29 APRIL 2012 | DOI: 10.1038/NCLIMATE1505 Impacts of wind farms on land a region in west-central Texas, where four of the world's largest wind farms are located7 . Our results farms relative to nearby non-wind-farm regions. We attribute this warming primarily to wind farms as its

Zhou, Liming

144

LIDAR Wind Speed Measurements of Evolving Wind Fields  

SciTech Connect (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

145

Comprehensive model to determine the effects of temperature and species fluctuations on reaction rates in turbulent reaction flows  

SciTech Connect (OSTI)

The use of silane (SiH4) as an effective ignitor and flame stabilizing pilot fuel is well documented. A reliable chemical kinetic mechanism for prediction of its behavior at the conditions encountered in the combustor of a SCRAMJET engine was calculated. The effects of hydrogen addition on hydrocarbon ignition and flame stabilization as a means for reduction of lengthy ignition delays and reaction times were studied. The ranges of applicability of chemical kinetic models of hydrogen-air combustors were also investigated. The CHARNAL computer code was applied to the turbulent reaction rate modeling.

Magnotti, F.; Diskin, G.; Matulaitis, J.; Chinitz, W.

1984-01-01T23:59:59.000Z

146

Multivariate analysis and prediction of wind turbine response to varying wind field characteristics based on machine learning  

E-Print Network [OSTI]

are often described by time-dependent statistical parameters such as mean wind speed, turbulence intensity, mean wind direction and vertical mean wind profile, which depends on the surface roughness (e.g. landMultivariate analysis and prediction of wind turbine response to varying wind field characteristics

Stanford University

147

Laser induced fluorescence measurements of ion velocity and temperature of drift turbulence driven sheared plasma flow in a linear helicon plasma device  

SciTech Connect (OSTI)

Using laser induced fluorescence (LIF), radial profiles of azimuthal ion fluid velocity and ion temperature are measured in the controlled shear de-correlation experiment (CSDX) linear helicon plasma device. Ion velocities and temperatures are derived from the measured Doppler broadened velocity distribution functions of argon ions. The LIF system employs a portable, high power (>300 mW), narrowband ({approx}1 MHz) tunable diode laser-based system operating at 668.614 nm. Previous studies in CSDX have shown the existence of a radially sheared azimuthal flow as measured with time delay estimation methods and Mach probes. Here, we report the first LIF measurements of sheared plasma fluid flow in CSDX. Above a critical magnetic field, the ion fluid flow profile evolves from radially uniform to peaked on axis with a distinct reversed flow region at the boundary, indicating the development of a sheared azimuthal flow. Simultaneously, the ion temperature also evolves from a radially uniform profile to a profile with a gradient. Measurements in turbulent and coherent drift wave mode dominated plasmas are compared.

Chakraborty Thakur, S.; Fedorczak, N.; Manz, P.; Tynan, G. R.; Xu, M. [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego, California 92093 (United States); Center for Energy Research, University of California at San Diego, San Diego, California 92093 (United States); McCarren, D.; Scime, E. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Lee, T. [Center for Energy Research, University of California at San Diego, San Diego, California 92093 (United States)

2012-08-15T23:59:59.000Z

148

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

SciTech Connect (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

149

20th Century Reanalysis Project Ensemble Gateway: 56 Estimates of World Temperature, Pressure, Humidity, and Wind, 1871-2010  

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

This site provides data from the 20th Century Reanalysis Project, offering temperature, pressure, humidity, and wind predictions in 200 km sections all around the earth from 1871 to 2010, every 6 hours, based on historical data. The ensemble mean and standard deviation for each value were calculated over a set of 56 simulations. Data for each of the 56 ensemble members are included here. The dataset consists of files in netCDF 4 format that are available for download from the National Energy Research. The goal of the 20th Century Reanalysis Project is to use a Kalman filter-based technique to produce a global trophospheric circulation dataset at four-times-daily resolution back to 1871. The only dataset available for the early 20th century consists of error-ridden hand-drawn analyses of the mean sea level pressure field over the Northern Hemisphere. Modern data assimilation systems have the potential to improve upon these maps, but prior to 1948, few digitized upper-air sounding observations are available for such a reanalysis. The global tropospheric circulation dataset will provide an important validation check on the climate models used to make 21st century climate projections....[copied from http://portal.nersc.gov/project/20C_Reanalysis/

150

Stochastic modeling of lift and drag dynamics under turbulent conditions  

E-Print Network [OSTI]

measurement. The model is being developed with the aim to integrate it into a general wind energy converter dynamics, drag dynamics. 1 Introduction Wind energy converters (WECs) are permanently exposed to turbulent.peinke@forwind.de in every second, which imposes different risks. The dynamical nature of the wind has a significant impact

Peinke, Joachim

151

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

Boyer, Edmond

152

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

E-Print Network [OSTI]

Modelling of offshore wind turbine wakes with the wind farm program FLaP Bernhard Lange(1) , Hans been extended to improve the description of wake development in offshore conditions, especially the low from the Danish offshore wind farm Vindeby. Vertical wake profiles and mean turbulence intensities

Heinemann, Detlev

153

Momentum transport in the vicinity of q{sub min} in reverse shear tokamaks due to ion temperature gradient turbulence  

SciTech Connect (OSTI)

We present an analytic study of momentum transport of tokamak plasmas in the vicinity of minimum safety factor (q) position in reversed magnetic shear configuration. Slab ion temperature gradient modes with an equilibrium flow profile are considered in this study. Quasi-linear calculations of momentum flux clearly show the novel effects of q-curvature on the generation of intrinsic rotation and mean poloidal flow without invoking reflectional symmetry breaking of parallel wavenumber (k{sub ?}). This q-curvature effect originates from the inherent asymmetry in k{sub ?} populations with respect to a rational surface due to the quadratic proportionality of k{sub ?} when q-curvature is taken into account. Discussions are made of possible implications of q-curvature induced plasma flows on internal transport barrier formation in reversed shear tokamaks.

Singh, Rameswar, E-mail: rameswar@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India) [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); Laboratoire de Physique des Plasmas, Ecole Polytechnique route de Saclay, 91128 Palaiseau Cedex (France); Singh, R [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India) [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Jhang, Hogun [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Center for Momentum Transport and Flow Organization, University of California, San Diego, California 92093 (United States); Center for Astrophysics and Space Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0424 (United States)

2014-01-15T23:59:59.000Z

154

Stability and Turbulence in the Atmospheric Boundary Layer: A Comparison of Remote Sensing and Tower Observations  

SciTech Connect (OSTI)

When monitoring winds and atmospheric stability for wind energy applications, remote sensing instruments present some advantages to in-situ instrumentation such as larger vertical extent, in some cases easy installation and maintenance, measurements of vertical humidity profiles throughout the boundary layer, and no restrictions on prevailing wind directions. In this study, we compare remote sensing devices, Windcube lidar and microwave radiometer, to meteorological in-situ tower measurements to demonstrate the accuracy of these measurements and to assess the utility of the remote sensing instruments in overcoming tower limitations. We compare temperature and wind observations, as well as calculations of Brunt-Vaisala frequency and Richardson numbers for the instrument deployment period in May-June 2011 at the U.S. Department of Energy National Renewable Energy Laboratory's National Wind Technology Center near Boulder, Colorado. The study reveals that a lidar and radiometer measure wind and temperature with the same accuracy as tower instruments, while also providing advantages for monitoring stability and turbulence. We demonstrate that the atmospheric stability is determined more accurately when the liquid-water mixing ratio derived from the vertical humidity profile is considered under moist-adiabatic conditions.

Friedrich, K.; Lundquist, J. K.; Aitken, M.; Kalina, E. A.; Marshall, R. F.

2012-01-01T23:59:59.000Z

155

Analysis of mixing layer heights inferred from radiosonde, wind profiler, airborne lidar, airborne microwave temperature profiler, and in-situ aircraft data during the Texas 2000 air quality study in Houston, TX  

E-Print Network [OSTI]

The mixing layer (ML) heights inferred from radiosondes, wind profilers, airborne lidar, airborne microwave temperature profiler (MTP), and in-situ aircraft data were compared during the Texas 2000 Air Quality Study in the Houston area...

Smith, Christina Lynn

2005-08-29T23:59:59.000Z

156

Wind Electrolysis: Hydrogen Cost Optimization  

SciTech Connect (OSTI)

This report describes a hydrogen production cost analysis of a collection of optimized central wind based water electrolysis production facilities. The basic modeled wind electrolysis facility includes a number of low temperature electrolyzers and a co-located wind farm encompassing a number of 3MW wind turbines that provide electricity for the electrolyzer units.

Saur, G.; Ramsden, T.

2011-05-01T23:59:59.000Z

157

ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE SOLAR WIND  

SciTech Connect (OSTI)

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

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

2013-09-20T23:59:59.000Z

158

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

SciTech Connect (OSTI)

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

159

Turbulent combustion  

SciTech Connect (OSTI)

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

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

1993-12-01T23:59:59.000Z

160

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

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Fifteen Lectures on Laminar and Turbulent Combustion  

E-Print Network [OSTI]

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

Peters, Norbert

162

Wind derivatives: hedging wind risk:.  

E-Print Network [OSTI]

??Wind derivatives are financial contracts that can be used to hedge or mitigate wind risk. In this thesis, the focus was on pricing these wind (more)

Hoyer, S.A.

2013-01-01T23:59:59.000Z

163

Electron Thermal Transport in Tokamak: ETG or TEM Turbulences?  

E-Print Network [OSTI]

Electron Thermal Transport in Tokamak: ETG or TEM Turbulences? Z. Lin, L. Chen, Y. Nishimura, H. Qu studies of electron transport in tokamak including: (1) electron temperature gradient turbulence; (2) trapped electron mode turbulence; and (3) a new finite element solver for global electromagnetic

Zonca, Fulvio

164

Inclusion of turbulence in solar modeling  

E-Print Network [OSTI]

The general consensus is that in order to reproduce the observed solar p-mode oscillation frequencies, turbulence should be included in solar models. However, until now there has not been any well-tested efficient method to incorporate turbulence into solar modeling. We present here two methods to include turbulence in solar modeling within the framework of the mixing length theory, using the turbulent velocity obtained from numerical simulations of the highly superadiabatic layer of the sun at three stages of its evolution. The first approach is to include the turbulent pressure alone, and the second is to include both the turbulent pressure and the turbulent kinetic energy. The latter is achieved by introducing two variables: the turbulent kinetic energy per unit mass, and the effective ratio of specific heats due to the turbulent perturbation. These are treated as additions to the standard thermodynamic coordinates (e.g. pressure and temperature). We investigate the effects of both treatments of turbulence on the structure variables, the adiabatic sound speed, the structure of the highly superadiabatic layer, and the p-mode frequencies. We find that the second method reproduces the SAL structure obtained in 3D simulations, and produces a p-mode frequency correction an order of magnitude better than the first method.

L. H. Li; F. J. Robinson; P. Demarque; S. Sofia; D. B. Guenther

2001-11-07T23:59:59.000Z

165

6, 52515268, 2006 Turbulent fluxes over  

E-Print Network [OSTI]

´exico, 04510 Mexico City, Mexico Received: 24 March 2006 ­ Accepted: 10 May 2006 ­ Published: 26 June 2006 wind speed conditions (up to 25 ms -1 ). The estimates of total momentum flux and turbulent kinetic energy can be represented very5 accurately (r2 =0.99, when data are binned every 1 ms-1 ) by empirical

Boyer, Edmond

166

Scaling turbulent atmospheric stratification: a turbulence/wave wind model  

E-Print Network [OSTI]

, it displays no wave-like phenomenol- ogy. We show how to extend the FIF model to account for more realistic

Lovejoy, Shaun

167

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

SciTech Connect (OSTI)

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

168

Passive Tomography of Turbulence Strength Marina Alterman1  

E-Print Network [OSTI]

expensive. Turbulence significantly affects the efficiency of wind turbine #12;2 M. Alterman, Y. Y), wind, and atmospheric stability. This is measured using special Doppler lidars [9, 31], which are very. Schechner, M. Vo and S. G. Narasimhan farms [31], hence optimizing turbines and farms involves measuring TS

Sheikh, Yaser Ajmal

169

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

170

aperiodic magnetic turbulence: Topics by E-print Network  

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

star formation and the interstellar medium. The density, pressure, and temperature distribution in a turbulent interstellar medium is described in comparison to a medium dominated...

171

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

172

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

SciTech Connect (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

173

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;

174

Comparison of anemometers for turbulence characterization  

SciTech Connect (OSTI)

During the first phase of the US Department of Energy's turbulence characterization program, important discoveries were made about the field application of propeller-vane and cup anemometers under very turbulent conditions. First, averaged speeds measured by the propeller-vane anemometer were consistently lower than those from the cup anemometer, even though both registered virtually the same during wind-tunnel calibration testing. Second, the propeller-vane anemometers suffered from structural failures much more frequently than the cup anemometers. The difficulties associated with the use of the propeller-vane motivated us to consider the cup anemometer for turbulence measurements. At fast sample rates, the output of the cup anemometer is severely degraded by discretization error that stems from pulse counting demodulation. However, we found that a low-pass Gaussian filter could be applied to the time series of wind speed derived from the cup anemometer to yield time series and frequency spectra that compared very favorably with those obtained from the propeller-vane anemometer. This finding suggests that the cup anemometer may prove to be an inexpensive and rugged sensor appropriate for turbulence measurements for wind-energy applications.

Morris, V.R.; Barnard, J.C.; Wendell, L.L.; Tomich, S.D.

1992-10-01T23:59:59.000Z

175

Session: Poster Session + Poster Award + Scientific Award + Excellent young wind doctor award (PO.121) Track: Technical  

E-Print Network [OSTI]

in turbulence intensity in wakes behind wind turbines can imply a significant reduction in fatigue lifetime by a stochastic part and a deterministic, sinusoidal part with frequency Behind a wind turbine a wake is formed intensity in wakes behind wind turbines can imply a significant reduction in the fatigue lifetime of wind

176

Estimation of uncertainties due to the wind-induced noise in a screened microphone  

E-Print Network [OSTI]

for experimental assessment of wind turbine noise. The contribution of the wind noise introduces a biasEstimation of uncertainties due to the wind-induced noise in a screened microphone D. Ecotiere by the wind at a screened microphone. This noise originates from turbulences that come from the direct

Paris-Sud XI, Université de

177

Session: Wind resources and site characterisation 2 (DW3.5) Track: Technical  

E-Print Network [OSTI]

including wind shear, turbulence intensities etc., at potential wind turbine positions. - ApplicationSession: Wind resources and site characterisation 2 (DW3.5) Track: Technical THE BOLUND EXPERIMENT - A NEW DATASET OF LOCAL WIND CONDITIONS IN COMPLEX TERRAIN (abstract-ID: 357) Jeppe Johansen (Risø DTU

178

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

E-Print Network [OSTI]

in the gross wind environment and in the extreme response given wind conditions to establish nominal designAIAA-2004-0502 1 A COMPARISON OF WIND TURBINE DESIGN LOADS IN DIFFERENT ENVIRONMENTS USING INVERSE, Austin, TX 78712 ABSTRACT* The influence of turbulence conditions on the design loads for wind turbines

Manuel, Lance

179

WIND ENERGY Wind Energ. (2014)  

E-Print Network [OSTI]

WIND ENERGY Wind Energ. (2014) Published online in Wiley Online Library (wileyonlinelibrary Correspondence M. Wächter, ForWind-Center for Wind Energy Research, Institute of Physics, Carl Von Ossietzky on the operation of wind energy converters (WECs) imposing different risks especially in terms of highly dynamic

Peinke, Joachim

180

Turbulent Compressibilty of Protogalactic Gas  

E-Print Network [OSTI]

The star formation rate in galaxies should be related to the fraction of gas that can attain densities large enough for gravitational collapse. In galaxies with a turbulent interstellar medium, this fraction is controlled by the effective barotropic index $gamma = dlog P/dlog (rho)$ which measures the turbulent compressibility. When the cooling timescale is smaller than the dynamical timescale, gamma can be evaluated from the derivatives of cooling and heating functions, using the condition of thermal equilibrium. We present calculations of gamma for protogalaxies in which the metal abundance is so small that H_2 and HD cooling dominates. For a heating rate independent of temperature and proportional to the first power of density, the turbulent gas is relatively "hard", with $gamma >= 1$, at large densities, but moderately "soft", $gamma <= 0.8$, at densities below around $10^4 cm^(-3)$. At low temperatures the density probability distribution should fall ra pidly for densities larger than this value, which corresponds physically to the critical density at which collisional and radiative deexcitation rate s of HD are equal. The densities attained in turbulent protogalaxies thus depend on the relatively large deuterium abundance in our universe. We expect the same physical effect to occur in higher metallicity gas with different coolants. The case in which adiabatic (compressional) heating due to cloud collapse dominates is also discussed, and suggests a criterion for the maximum mass of Population III stars.

John Scalo; Anirban Biswas

2001-11-09T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Free Energy Cascade in Gyrokinetic Turbulence  

SciTech Connect (OSTI)

In gyrokinetic theory, the quadratic nonlinearity is known to play an important role in the dynamics by redistributing (in a conservative fashion) the free energy between the various active scales. In the present study, the free energy transfer is analyzed for the case of ion temperature gradient driven turbulence. It is shown that it shares many properties with the energy transfer in fluid turbulence. In particular, one finds a (strongly) local, forward (from large to small scales) cascade of free energy in the plane perpendicular to the background magnetic field. These findings shed light on some fundamental properties of plasma turbulence, and encourage the development of large-eddy-simulation techniques for gyrokinetics.

Banon Navarro, A.; Morel, P.; Albrecht-Marc, M.; Carati, D. [Universite Libre de Bruxelles, Faculte des Sciences, Physique Statistique et Plasmas CP 231, EURATOM Association, Campus Plaine, 1050 Brussels (Belgium); Merz, F.; Goerler, T.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany)

2011-02-04T23:59:59.000Z

182

WIND ENERGY Wind Energ. (2014)  

E-Print Network [OSTI]

in the near wake. In conclusion, WiTTS performs satisfactorily in the rotor region of wind turbine wakes under neutral stability. Copyright 2014 John Wiley & Sons, Ltd. KEYWORDS wind turbine wake; wake model; self in wind farms along several rows and columns. Because wind turbines generate wakes that propagate downwind

2014-01-01T23:59:59.000Z

183

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

2010-06-05T23:59:59.000Z

184

Wind Circulation in Selected Rotating Magnetic Early-B Stars  

E-Print Network [OSTI]

The rotating magnetic B stars have oblique dipolar magnetic fields and often anomalous helium and metallic compositions. These stars develop co-rotating torus-shaped clouds by channelling winds from their magnetic poles to an anchored planar disk over the magnetic equator. The line absorptions from the cloud can be studied as the complex rotates and periodically occults the star. We describe an analysis of the clouds of four stars (HD184927, beta Cep, sigma Ori E, and HR6684). From line synthesis models, we find that the metallic compositions are spatially uniform over the stars' surfaces. Next, using the Hubeny CIRCUS code, we demonstate that periodic UV continuum fluxes can be explained by the absorption of low-excitation lines. The analysis also quantifies the cloud temperatures, densities, and turbulences, which appear to increase inward toward the stars. The temperatures range from about 12,000K for the weak Fe lines up to temperatures of 33,000K for N V absorptions, which is in excess of temperatures expected from radiative equilibrium. The spectroscopic hallmark of this stellar class is the presence of strong C IV and N V resonance line absorptions at occultation phases and of redshifted emissions at magnetic pole-on phases. The emissions have characteristics which seem most compatible with the generation of high-energy shocks at the wind-cloud interface, as predicted by Babel.

Myron A. Smith; Detlef Groote

2001-04-03T23:59:59.000Z

185

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

186

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

187

Stellar Winds on the Main-Sequence I: Wind Model  

E-Print Network [OSTI]

Aims: We develop a method for estimating the properties of stellar winds for low-mass main-sequence stars between masses of 0.4 and 1.1 solar masses at a range of distances from the star. Methods: We use 1D thermal pressure driven hydrodynamic wind models run using the Versatile Advection Code. Using in situ measurements of the solar wind, we produce models for the slow and fast components of the solar wind. We consider two radically different methods for scaling the base temperature of the wind to other stars: in Model A, we assume that wind temperatures are fundamentally linked to coronal temperatures, and in Model B, we assume that the sound speed at the base of the wind is a fixed fraction of the escape velocity. In Paper II of this series, we use observationally constrained rotational evolution models to derive wind mass loss rates. Results: Our model for the solar wind provides an excellent description of the real solar wind far from the solar surface, but is unrealistic within the solar corona. We run ...

Johnstone, C P; Lftinger, T; Toth, G; Brott, I

2015-01-01T23:59:59.000Z

188

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

SciTech Connect (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

189

Assessing the Evolution of the Solar Wind through the Spectrum of Velocity Fluctuations from 1 5 AU.  

E-Print Network [OSTI]

;2 Abstract: Turbulent processes occur in the solar wind and contribute to solar wind evolution and heating assistance he's provided. #12;4 Contents 1. The Solar Wind 1.1 Early Remote Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 #12;5 Chapter 1 The Solar Wind 1.1 Early Remote Observations The earliest observations of the sun

190

Passively cooled direct drive wind turbine  

DOE Patents [OSTI]

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

191

Under consideration for publication in J. Fluid Mech. 1 Realizing turbulent statistics  

E-Print Network [OSTI]

be reproduced at the inflow?". We present a technique able to produce a random field with the exact two on our system. Suppose that we are interested in the wake of a cylinder in a fully turbulent flow, as could be realized experimentally by placing a turbulence generating grid in a wind tunnel, upstream

Hoepffner, Jérôme

192

Turbulence-chemistry interactions in reacting flows  

SciTech Connect (OSTI)

Interactions between turbulence and chemistry in nonpremixed flames are investigated through multiscalar measurements. Simultaneous point measurements of major species, NO, OH, temperature, and mixture fraction are obtained by combining spontaneous Raman scattering, Rayleigh scattering, and laser-induced fluorescence (LIF). NO and OH fluorescence signals are converted to quantitative concentrations by applying shot-to-shot corrections for local variations of the Boltzmann fraction and collisional quenching rate. These measurements of instantaneous thermochemical states in turbulent flames provide insights into the fundamental nature of turbulence-chemistry interactions. The measurements also constitute a unique data base for evaluation and refinement of turbulent combustion models. Experimental work during the past year has focused on three areas: (1) investigation of the effects of differential molecular diffusion in turbulent combustion: (2) experiments on the effects of Halon CF{sub 3}Br, a fire retardant, on the structure of turbulent flames of CH{sub 4} and CO/H{sub 2}/N{sub 2}; and (3) experiments on NO formation in turbulent hydrogen jet flames.

Barlow, R.S.; Carter, C.D. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

193

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

SciTech Connect (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

194

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

SciTech Connect (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

195

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

E-Print Network [OSTI]

with such spectral models can be in turn highly variable for different realizations. Turbine load and performance a wind velocity field over spatial dimensions on the scale of the turbine rotor diameter in accordance of uncertainty in inflow turbulence to wind turbine loads Korn Saranyasoontorn, Lance Manuel? Department of Civil

Manuel, Lance

196

Wind Farm  

Office of Energy Efficiency and Renewable Energy (EERE)

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

197

A COOLING SYSTEM FOR BUIDINGS USING WIND ENERGY  

E-Print Network [OSTI]

A COOLING SYSTEM FOR BUIDINGS USING WIND ENERGY Hamid Daiyan Islamic Azad University - Semnan in dray land, and only uses wind energy for conditioning. It technologies date back over 1000 years. Wind system, Wind energy, Temperature Fig.1 Wind tower of Doulat-Abad garden of Yazd with it's altitude is 33

198

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

E-Print Network [OSTI]

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

Dabiri, John O.

199

Aspects of Wave Turbulence in Preheating  

E-Print Network [OSTI]

In this work we have studied the nonlinear preheating dynamics of the $\\frac{1}{4} \\lambda \\phi^4$ inflationary model. It is well established that after a linear stage of preheating characterized by the parametric resonance, the nonlinear dynamics becomes relevant driving the system towards turbulence. Wave turbulence is the appropriated description of this phase since matter distributions are fields instead of usual fluids. Therefore, turbulence develops due to the nonlinear interations of waves, here represented by the small inhomogeneities of the inflaton field. We present relevant aspects of wave turbulence such as the Kolmogorov-Zakharov spectrum in frequency and wave number domains that indicates that there are a transfer of energy through scales. From the power spectrum of the matter energy density we were able to estimate the temperature of the thermalized system.

Jos A. Crespo; H. P. de Oliveira

2014-06-04T23:59:59.000Z

200

Advances in three-dimensional turbulence measurement capability  

SciTech Connect (OSTI)

Requirements for three-dimensional turbulence velocity measurements for wind turbine purposes have recently led to advances in anemometer accuracy and resolution, particularly for situations when the angle of the wind relative to the anemometer axis is large. New precision calibration data for a complete three-dimensional UVW propeller anemometer are presented. Repeatability of calibration data and comparison with previous calibrations are shown. Special attention is given to the calibration of the crosswind components, V and W. 4 refs., 9 figs.

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

1988-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Wind Energy  

Broader source: Energy.gov [DOE]

Presentation covers wind energy at the Federal Utility Partnership Working Group (FUPWG) meeting, held on November 18-19, 2009.

202

The energetic coupling of scales in gyrokinetic plasma turbulence  

SciTech Connect (OSTI)

In magnetized plasma turbulence, the couplings of perpendicular spatial scales that arise due to the nonlinear interactions are analyzed from the perspective of the free-energy exchanges. The plasmas considered here, with appropriate ion or electron adiabatic electro-neutrality responses, are described by the gyrokinetic formalism in a toroidal magnetic geometry. Turbulence develops due to the electrostatic fluctuations driven by temperature gradient instabilities, either ion temperature gradient (ITG) or electron temperature gradient (ETG). The analysis consists in decomposing the system into a series of scale structures, while accounting separately for contributions made by modes possessing special symmetries (e.g., the zonal flow modes). The interaction of these scales is analyzed using the energy transfer functions, including a forward and backward decomposition, scale fluxes, and locality functions. The comparison between the ITG and ETG cases shows that ETG turbulence has a more pronounced classical turbulent behavior, exhibiting a stronger energy cascade, with implications for gyrokinetic turbulence modeling.

Teaca, Bogdan, E-mail: bogdan.teaca@coventry.ac.uk [Applied Mathematics Research Centre, Coventry University, Coventry CV1 5FB (United Kingdom); Max-Planck fr Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Gttingen (Germany); Max-Planck-Institut fr Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Max-Planck/Princeton Center for Plasma Physics (Germany); Navarro, Alejandro Ban, E-mail: alejandro.banon.navarro@ipp.mpg.de [Max-Planck-Institut fr Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Jenko, Frank, E-mail: frank.jenko@ipp.mpg.de [Max-Planck-Institut fr Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Max-Planck/Princeton Center for Plasma Physics (Germany)

2014-07-15T23:59:59.000Z

203

American Institute of Aeronautics and Astronautics A Framework for the Reliability Analysis of Wind Turbines  

E-Print Network [OSTI]

of Wind Turbines against Windstorms and Non-Standard Inflow Definitions Lance Manuel1 Dept. of Civil typical wind turbine systems are yet to be characterized in ways that drive aeroelastic loads and design., but the coherence structure and turbulence kinetics at the spatial scale of wind turbine rotors are not as well

Manuel, Lance

204

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

E-Print Network [OSTI]

? Unlike conventional power plants, where a wind turbine is located has a major effect on the amount and maintenance equipment. Distance to transmission lines and loads ­ Elec- tricity generated by a wind turbine of surface roughness. Taller towers can also be used to get the rotor above the turbulent zone. · · Wind

Massachusetts at Amherst, University of

205

Estimate of Extreme Wind, Wave, Surge, and Current Conditions Wilmington Canyon Integrated Design Project  

E-Print Network [OSTI]

1 Estimate of Extreme Wind, Wave, Surge, and Current Conditions for the Wilmington Canyon. In order to estimate loads during extreme wind and wave events, these events must be defined. The design. This paper does not treat wave spectral analysis, extreme wind shear, veer, clocking, turbulence intensity

Firestone, Jeremy

206

Wind loading on solar collectors  

SciTech Connect (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

207

Automatic storm protection control for wind energy system  

SciTech Connect (OSTI)

A wind energy plant is protected against damage from high winds by permitting the propeller assembly thereof to fold with respect to the tail assembly of the plant when the wind velocity with respect to the plant exceeds a predetermined value. Return of the propeller assembly to a wind facing orientation is controlled to prevent oscillating or whipping in gusty or turbulent winds. A safety system is included to control plant shutdown, and automatically shuts down the plant if the plant is being subjected to excessive vibration.

Jacobs, M.L.; Jacobs, P.R.

1981-10-27T23:59:59.000Z

208

An overview: Challenges in wind technology development  

SciTech Connect (OSTI)

Developing innovative wind turbine components and advanced turbine configurations is a primary focus for wind technology researchers. In their rush to bring these new components and systems to the marketplace, designers and developers should consider the lessons learned in the wind farms over the past 10 years. Experience has shown that a disciplined design approach is required that realistically accounts for the turbulence-induced loads, unsteady stall loading, and fatigue effects. This paper reviews past experiences and compares current modelling capabilities with experimental measurements in order to identify some of the knowledge gaps that challenge designers of advanced components and systems. 7 refs., 11 figs.

Thresher, R W; Hock, S M

1991-12-01T23:59:59.000Z

209

The evaluation of a turbulent loads characterization system  

SciTech Connect (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

210

Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization  

SciTech Connect (OSTI)

Wind is a significant source of energy; however, the human capability to produce electrical energy still has many hurdles to overcome. One of these is the unpredictability of the winds in the atmospheric boundary layer (ABL). The ABL is highly turbulent in both stable and unstable conditions (based on the vertical temperature profile) and the resulting fluctuations can have a dramatic impact on wind turbine operation. Any method by which these fluctuations could be observed, estimated, or predicted could provide a benefit to the wind energy industry as a whole. Based on the fundamental coupling of velocity fluctuations to pressure fluctuations in the nearly incompressible flow in the ABL, This work hypothesizes that a ground-based array of infrasonic pressure transducers could be employed to estimate the vertical wind profile over a height relevant for wind turbines. To analyze this hypothesis, experiments and field deployments were conducted. Wind tunnel experiments were performed for a thick turbulent boundary layer over a neutral or heated surface. Surface pressure and velocity probe measurements were acquired simultaneously. Two field deployments yielded surface pressure data from a 49 element array. The second deployment at the Reese Technology Center in Lubbock, TX, also included data from a smaller aperture, 96-element array and a 200-meter tall meteorological tower. Analysis of the data successfully demonstrated the ability to estimate the vertical velocity profile using coherence data from the pressure array. Also, dynamical systems analysis methods were successful in identifying and tracking a gust type event. In addition to the passive acoustic profiling method, this program also investigated a rapid response Doppler SODAR system, the optimization of wind turbine blades for enhanced power with reduced aeroacoustic noise production, and the implementation of a wireless health monitoring system for the wind turbine blades. Each of these other objectives was met successfully. The use of phase unwrapping applied to SODAR data was found to yield reasonable results for per-pulse measurements. A health monitoring system design analysis was able to demonstrate the ability to use a very small number of sensors to monitor blade health based on the blade's overall structural modes. Most notable was the development of a multi-objective optimization methodology that successfully yielded an aerodynamic blade design that produces greater power output with reduced aerodynamic loading noise. This optimization method could be significant for future design work.

Murray, Nathan E.

2012-03-12T23:59:59.000Z

211

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

E-Print Network [OSTI]

of the interstellar medium,1 acceleration of the solar wind,2,3 solar coronal heating,4 trans- port of energy and mass, Valdosta, Georgia 31698, USA 2 Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa heating, acceleration of the solar wind, and heating of the interstellar medium. Turbulence

California at Los Angles, University of

212

Strong wind forcing of the ocean  

E-Print Network [OSTI]

the wind field should 'feel' the effects of the cold wake, awind stress leaves behind a wake of near inertial currents and modified temperature field,

Zedler, Sarah E.

2007-01-01T23:59:59.000Z

213

Wind turbine  

SciTech Connect (OSTI)

The improvement in a wind turbine comprises providing a tower with a freely liftable mount and adapting a nacelle which is fitted with a propeller windwheel consisting of a plurality of rotor blades and provided therein with means for conversion of wind energy to be shifted onto said mount attached to the tower. In case of a violent wind storm, the nacelle can be lowered down to the ground to protect the rotor blades from breakage due to the force of the wind. Required maintenance and inspection of the nacelle and replacement of rotor blades can be safely carried out on the ground.

Abe, M.

1982-01-19T23:59:59.000Z

214

Experimental Signatures of Critically Balanced Turbulence in MAST  

E-Print Network [OSTI]

Beam emission spectroscopy (BES) measurements of ion-scale density fluctuations in the MAST tokamak are used to show that the turbulence correlation time, the drift time associated with ion temperature or density gradients, ...

Ghim, Y.-c.

215

Quasigeostrophic Turbulence with Explicit Surface Dynamics: Application to the Atmospheric Energy Spectrum  

E-Print Network [OSTI]

, plots power density spectra of the zonal wind (u2 ), meridional wind (y2 ), and the potential temperature (u2 ) as func- tions of horizontal wavenumber (meridional wind and potential temperature and spectral break, but is about half the magnitude of the spectra of the winds. The available potential energy

Smith, K. Shafer

216

Coastal Microstructure: From Active Overturn to Fossil Turbulence  

E-Print Network [OSTI]

.................................................................................... 33 Figure 10. Front view of the sensor package installed on MSS profiler including two shear probes, micro-temperature, micro-conductivity, accurate- temperature, accurate-conductivity, acceleration, turbidity, and depth sensors... frequently used in oceanography. A very important characteristic of turbulence is that it produces highly persistent, irreversible effects in a variety of hydro-physical fields. Linear waves come and go without leaving any trace, but turbulence...

Leung, Pak Tao

2012-02-14T23:59:59.000Z

217

OBSERVATION OF FLUX-TUBE CROSSINGS IN THE SOLAR WIND  

SciTech Connect (OSTI)

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

Arnold, L.; Li, G.; Li, X. [Department of Physics and CSPAR, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)] [Department of Physics and CSPAR, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Yan, Y., E-mail: gang.li@uah.edu [Key Laboratory of Solar Activity, National Astronomical Observatories of Chinese Academy of Sciences, Beijing 100012 (China)

2013-03-20T23:59:59.000Z

218

Dissipation in Turbulent Plasma due to Reconnection in Thin Current Sheets David Sundkvist,1,* Alessandro Retino`,2  

E-Print Network [OSTI]

to kinetic and thermal particle energies. In this Letter we use space plasma as a turbulence laboratory the strongly turbulent solar wind down- stream of Earth's bow shock, the so-called magnetosheath (magnetic field), and CIS (ions) experiments [17]. At 09:35 UT the spacecraft crossed the bow shock

California at Berkeley, University of

219

Free energy balance in gyrokinetic turbulence  

SciTech Connect (OSTI)

Free energy plays an important role in gyrokinetic theory, since it is known to be a nonlinear invariant. Its evolution equations are derived and analyzed for the case of ion temperature gradient driven turbulence, using the formalism adopted in the Gene code. In particular, the ion temperature gradient drive, the collisional dissipation as well as entropy/electrostatic energy transfer channels represented by linear curvature and parallel terms are analyzed in detail.

Banon Navarro, A.; Morel, P.; Albrecht-Marc, M.; Carati, D. [Statistical and Plasma Physics Laboratory, Universite Libre de Bruxelles (Belgium); Merz, F.; Goerler, T.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany)

2011-09-15T23:59:59.000Z

220

Wind speed vertical distribution at Mt. Graham  

E-Print Network [OSTI]

The characterization of the wind speed vertical distribution V(h) is fundamental for an astronomical site for many different reasons: (1) the wind speed shear contributes to trigger optical turbulence in the whole troposphere, (2) a few of the astroclimatic parameters such as the wavefront coherence time (tau_0) depends directly on V(h), (3) the equivalent velocity V_0, controlling the frequency at which the adaptive optics systems have to run to work properly, depends on the vertical distribution of the wind speed and optical turbulence. Also, a too strong wind speed near the ground can introduce vibrations in the telescope structures. The wind speed at a precise pressure (200 hPa) has frequently been used to retrieve indications concerning the tau_0 and the frequency limits imposed to all instrumentation based on adaptive optics systems, but more recently it has been proved that V_200 (wind speed at 200 hPa) alone is not sufficient to provide exhaustive elements concerning this topic and that the vertical d...

Hagelin, S; Lascaux, F

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

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

222

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

E-Print Network [OSTI]

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

Polly, David

223

Turbulent Transport in Tokamak Plasmas with Rotational Shear  

SciTech Connect (OSTI)

Nonlinear gyrokinetic simulations are conducted to investigate turbulent transport in tokamak plasmas with rotational shear. At sufficiently large flow shears, linear instabilities are suppressed, but transiently growing modes drive subcritical turbulence whose amplitude increases with flow shear. This leads to a local minimum in the heat flux, indicating an optimal ExB shear value for plasma confinement. Local maxima in the momentum fluxes are observed, implying the possibility of bifurcations in the ExB shear. The critical temperature gradient for the onset of turbulence increases with flow shear at low flow shears; at higher flow shears, the dependence of heat flux on temperature gradient becomes less stiff. The turbulent Prandtl number is found to be largely independent of temperature and flow gradients, with a value close to unity.

Barnes, M.; Highcock, E. G. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom); Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Parra, F. I.; Schekochihin, A. A. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom); Cowley, S. C.; Roach, C. M. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2011-04-29T23:59:59.000Z

224

20% Wind Energy 20% Wind Energy  

E-Print Network [OSTI]

(government, industry, utilities, NGOs) Analyzes wind's potential contributions to energy security, economic · Transmission a challenge #12;Wind Power Class Resource Potential Wind Power Density at 50 m W/m 2 Wind Speed20% Wind Energy by 2030 20% Wind Energy by 2030 #12;Presentation and Objectives Overview Background

Powell, Warren B.

225

Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD  

SciTech Connect (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

226

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"

227

Boundary Plasma Turbulence Simulations for Tokamaks  

SciTech Connect (OSTI)

The boundary plasma turbulence code BOUT models tokamak boundary-plasma turbulence in a realistic divertor geometry using modified Braginskii equations for plasma vorticity, density (ni), electron and ion temperature (T{sub e}; T{sub i}) and parallel momenta. The BOUT code solves for the plasma fluid equations in a three dimensional (3D) toroidal segment (or a toroidal wedge), including the region somewhat inside the separatrix and extending into the scrape-off layer; the private flux region is also included. In this paper, a description is given of the sophisticated physical models, innovative numerical algorithms, and modern software design used to simulate edge-plasmas in magnetic fusion energy devices. The BOUT code's unique capabilities and functionality are exemplified via simulations of the impact of plasma density on tokamak edge turbulence and blob dynamics.

Xu, X; Umansky, M; Dudson, B; Snyder, P

2008-05-15T23:59:59.000Z

228

PERPENDICULAR ION HEATING BY REDUCED MAGNETOHYDRODYNAMIC TURBULENCE  

SciTech Connect (OSTI)

Recent theoretical studies argue that the rate of stochastic ion heating in low-frequency Alfvn-wave turbulence is given by Q = c{sub 1}((?u){sup 3}/?)exp ( c{sub 2}/?), where ?u is the rms turbulent velocity at the scale of the ion gyroradius ?, ? = ?u/v{sub i}, v{sub i} is the perpendicular ion thermal speed, and c{sub 1} and c{sub 2} are dimensionless constants. We test this theoretical result by numerically simulating test particles interacting with strong reduced magnetohydrodynamic (RMHD) turbulence. The heating rates in our simulations are well fit by this formula. The best-fit values of c{sub 1} are ?1. The best-fit values of c{sub 2} decrease (i.e., stochastic heating becomes more effective) as the Reynolds number and the number of grid points in the RMHD simulations increase. As an example, in a 1024{sup 2} 256 RMHD simulation with a dissipation wavenumber of the order of the inverse ion gyroradius, we find c{sub 2} = 0.21. We show that stochastic heating is significantly stronger in strong RMHD turbulence than in a field of randomly phased Alfvn waves with the same power spectrum, because coherent structures in strong RMHD turbulence increase orbit stochasticity in the regions where ions are heated most strongly. We find that c{sub 1} increases by a factor of ?3 while c{sub 2} changes very little as the ion thermal speed increases from values <wind.

Xia, Qian; Perez, Jean C.; Chandran, Benjamin D. G. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH (United States); Quataert, Eliot, E-mail: qdy2@unh.edu, E-mail: benjamin.chandran@unh.edu, E-mail: jeanc.perez@unh.edu, E-mail: eliot@astro.berkeley.edu [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, The University of California, Berkeley, CA 94720 (United States)

2013-10-20T23:59:59.000Z

229

E-Print Network 3.0 - atmospheric wind sensor Sample Search Results  

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

to measure wind speed, wind direction, air... temperature, atmospheric pressure and solar radiation. The sensors and data-logger are mounted on 25-m high... calibration of...

230

NO concentration imaging in turbulent nonpremixed flames  

SciTech Connect (OSTI)

The importance of NO as a pollutant species is well known. An understanding of the formation characteristics of NO in turbulent hydrocarbon flames is important to both the desired reduction of pollutant emissions and the validation of proposed models for turbulent reacting flows. Of particular interest is the relationship between NO formation and the local flame zone, in which the fuel is oxidized and primary heat release occurs. Planar imaging of NO provides the multipoint statistics needed to relate NO formation to the both the flame zone and the local turbulence characteristics. Planar imaging of NO has been demonstrated in turbulent flames where NO was seeded into the flow at high concentrations (2000 ppm) to determine the gas temperature distribution. The NO concentrations in these experiments were significantly higher than those expected in typical hydrocarbon-air flames, which require a much lower detectability limit for NO measurements. An imaging technique based on laser-induced fluorescence with sufficient sensitivity to study the NO formation mechanism in the stabilization region of turbulent lifted-jet methane flames.

Schefer, R.W. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

231

Generalized universal instability: Transient linear amplification and subcritical turbulence  

E-Print Network [OSTI]

In this work we numerically demonstrate both significant transient (i.e. non-modal) linear amplification and sustained nonlinear turbulence in a kinetic plasma system with no unstable eigenmodes. The particular system considered is an electrostatic plasma slab with magnetic shear, kinetic electrons and ions, weak collisions, and a density gradient, but with no temperature gradient. In contrast to hydrodynamic examples of non-modal growth and subcritical turbulence, here there is no sheared flow in the equilibrium. Significant transient linear amplification is found when the magnetic shear and collisionality are weak. It is also demonstrated that nonlinear turbulence can be sustained if initialized at sufficient amplitude. We prove these two phenomena are related: when sustained turbulence occurs without unstable eigenmodes, states that are typical of the turbulence must yield transient linear amplification of the gyrokinetic free energy.

Landreman, Matt; Dorland, William

2015-01-01T23:59:59.000Z

232

Combustion-turbulence interaction in the turbulent boundary layer over a hot surface  

SciTech Connect (OSTI)

The turbulence-combustion interaction in a reacting turbulent boundary layer over a heated flat plate was studied. Ethylene/air mixture with equivalence ratio of 0.35 was used. The free stream velocity was 10.5 m/s and the wall temperature was 1250/sup 0/K. Combustion structures visualization was provided by high-speed schlieren photographs. Fluid density statistics were deduced from Rayleigh scattering intensity measurements. A single-component laser Doppler velocimetry system was used to obtain mean and root-mean-square velocity distributions, the Reynolds stress, the streamwise and the cross-stream turbulent kinetic energy diffusion, and the production of turbulent kinetic energy by Reynolds stress. The combustion process was dominated by large-scale turbulent structures of the boundary layer. Combustion causes expansion of the boundary layer. No overall self-similarity is observed in either the velocity or the density profiles. Velocity fluctuations were increased in part of the boundary layer and the Reynolds stress was reduced. The turbulent kinetic energy diffusion pattern was changed significantly and a modification of the boundary layer assumption will be needed when dealing with this problem analytically. 11 figures, 1 table.

Ng, T.T.; Cheng, R.K.; Robben, F.; Talbot, L.

1982-01-01T23:59:59.000Z

233

Information Content of Turbulence  

E-Print Network [OSTI]

We treat a turbulent velocity field as a message in the same way as a book or a picture. All messages can be described by their entropy per symbol $h$, defined as in Shannon's theory of communication. In a turbulent flow, as the Reynolds number $Re$ increases, more correlated degrees of freedom are excited and participate in the turbulent cascade. Experiments in a turbulent soap film suggest that the spatial entropy density $h$ is a decreasing function of $Re$, namely $h \\propto -\\log Re$ + const. In the logistic map, also analyzed here, increasing the control parameter $r$ increases $h$. A modified logistic map with additional coupling to past iterations suggests the significance of correlations.

Rory Cerbus; Walter Goldburg

2013-07-03T23:59:59.000Z

234

Ignition of hydrogen/air mixing layer in turbulent flows  

SciTech Connect (OSTI)

Autoignition of a scalar hydrogen/air mixing layer in homogeneous turbulence is studied using direct numerical simulation. An initial counterflow of unmixed nitrogen-diluted hydrogen and heated air is perturbed by two-dimensional homogeneous turbulence. The temperature of the heated air stream is chosen to be 1,100 K which is substantially higher than the crossover temperature at which the rates of the chain branching and termination reactions become equal. Three different turbulence intensities are tested in order to assess the effect of the characteristic flow time on the ignition delay. For each condition, a simulation without heat release is also performed. The ignition delay determined with and without heat release is shown to be almost identical up to the point of ignition for all of the turbulence intensities tested, and the predicted ignition delays agree well within a consistent error band. It is also observed that the ignition kernel always occurs where hydrogen is focused, and the peak concentration of HO{sub 2} is aligned well with the scalar dissipation rate. The dependence of the ignition delay on turbulence intensity is found to be nonmonotonic. For weak to moderate turbulence the ignition is facilitated by turbulence via enhanced mixing, while for stronger turbulence, whose timescale is substantially smaller than the ignition delay, the ignition is retarded due to excessive scalar dissipation, and hence diffusive loss, at the ignition location. However, for the wide range of initial turbulence fields studied, the variation in ignition delay due to the corresponding variation in turbulence intensity appears to be quite small.

Im, H.G.; Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Law, C.K. [Princeton Univ., NJ (United States). Dept. of Mechanical and Aerospace Engineering

1998-03-01T23:59:59.000Z

235

Wind Energy Benefits, Wind Powering America (WPA) (Fact Sheet...  

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

Energy Benefits, Wind Powering America (WPA) (Fact Sheet), Wind And Water Power Program (WWPP) Wind Energy Benefits, Wind Powering America (WPA) (Fact Sheet), Wind And Water Power...

236

Aleutian Pribilof Islands Wind Energy Feasibility Study  

SciTech Connect (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

237

Dynamic stall on wind turbine blades  

SciTech Connect (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

238

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

that includes wind turbine towers. 2011 Wind TechnologiesSets Other Wind Turbine Components Towers Wind-Poweredselected wind turbine components includes towers as well as

Bolinger, Mark

2013-01-01T23:59:59.000Z

239

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

that includes wind turbine towers. 2010 Wind TechnologiesImports : Other Wind Turbine Components Towers Wind-Poweredselected wind turbine components includes towers as well as

Wiser, Ryan

2012-01-01T23:59:59.000Z

240

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

E-Print Network [OSTI]

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

Leu, Tzong-Shyng "Jeremy"

Note: This page contains sample records for the topic "temperature turbulence wind" 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

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)

lker, Muhammed Akif

2011-01-01T23:59:59.000Z

242

Energy 101: Wind Turbines  

SciTech Connect (OSTI)

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

None

2011-01-01T23:59:59.000Z

243

Energy 101: Wind Turbines  

ScienceCinema (OSTI)

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

None

2013-05-29T23:59:59.000Z

244

NREL: Wind Research - Events  

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

Events Below are upcoming events related to wind energy technology. January 2015 2015 Wind Energy Systems Engineering Workshop January 14 - 15, 2015 Boulder, CO The third NREL Wind...

245

Wind power and Wind power and  

E-Print Network [OSTI]

Wind power and the CDM #12; Wind power and the CDM Emerging practices in developing wind power 2005 Jyoti P. Painuly, Niels-Erik Clausen, Jørgen Fenhann, Sami Kamel and Romeo Pacudan #12; WIND POWER AND THE CDM Emerging practices in developing wind power projects for the Clean Development Mechanism Energy

246

Dispersed Phase of Non-Isothermal Particles in Rotating Turbulent Flows  

E-Print Network [OSTI]

We suggest certain effects, caused by interaction between rotation and gravitation with turbulence structure, for the cooling/heating of dispersed phase of non-isothermal particles in rotating turbulent fluid flows. These effects are obtained through the derivation of kinetic or probability density function based macroscopic equations for the particles. In doing so, for one-way temperature coupling, we also show that homogeneous, isotropic non-isothermal fluid turbulence does not influence the mean temperature (though it influences mean velocity) of the dispersed phase of particles settling due to gravitational force in the isotropic turbulence.

Pandya, R V R

2015-01-01T23:59:59.000Z

247

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

248

Turbulence Structure and Wall Signature in Hypersonic Turbulent Boundary Layer  

E-Print Network [OSTI]

Turbulence Structure and Wall Signature in Hypersonic Turbulent Boundary Layer Yin-Chiu Kan , Clara and hypersonic turbulent boundary layer datasets from direct numerical simulation (DNS). Contour plots and Marusic5 and Mathis, Hutchins and Marusic16 ). In contrast to supersonic and hypersonic flow regimes

Martín, Pino

249

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

250

Assessment of research needs for wind turbine rotor materials technology  

SciTech Connect (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

251

Simulated performance of an airborne lidar wind shear detection system  

E-Print Network [OSTI]

in the microburst test case. Journal model is Applied Optics. CHAPTER II THE WIND SHEAR HAZARD 2. 1 The Wind Shear Phenomenon Wind shear can be defined as a change in wind direction and/or speed over relatively short distances. i Wind shear can occur at any... and sea ? breeze fronts. These clear air winds move at speeds of 15 to 40 knots over large distances. rhtrrM~s Prost i ? arhiog the ar e of t a sitio bet eea t o separate ai masses having different temperatures and humidities. The change in wind...

Griffith, Kenneth Scott

2012-06-07T23:59:59.000Z

252

Strong Imbalanced Turbulence  

E-Print Network [OSTI]

We consider stationary, forced, imbalanced, or cross-helical MHD Alfvenic turbulence where the waves traveling in one direction have higher amplitudes than the opposite waves. This paper is dedicated to so-called strong turbulence, which cannot be treated perturbatively. Our main result is that the anisotropy of the weak waves is stronger than the anisotropy of a strong waves. We propose that critical balance, which was originally conceived as a causality argument, has to be amended by what we call a propagation argument. This revised formulation of critical balance is able to handle the imbalanced case and reduces to old formulation in the balanced case. We also provide phenomenological model of energy cascading and discuss possibility of self-similar solutions in a realistic setup of driven turbulence.

A. Beresnyak; A. Lazarian

2008-07-07T23:59:59.000Z

253

AMBIPOLAR DIFFUSION HEATING IN TURBULENT SYSTEMS  

SciTech Connect (OSTI)

The temperature of the gas in molecular clouds is a key determinant of the characteristic mass of star formation. Ambipolar diffusion (AD) is considered one of the most important heating mechanisms in weakly ionized molecular clouds. In this work, we study the AD heating rate using two-fluid turbulence simulations and compare it with the overall heating rate due to turbulent dissipation. We find that for observed molecular clouds, which typically have Alfven Mach numbers of {approx}1 and AD Reynolds numbers of {approx}20, about 70% of the total turbulent dissipation is in the form of AD heating. AD has an important effect on the length scale where energy is dissipated: when AD heating is strong, most of the energy in the cascade is removed by ion-neutral drift, with a comparatively small amount of energy making it down to small scales. We derive a relation for the AD heating rate that describes the results of our simulations to within a factor of two. Turbulent dissipation, including AD heating, is generally less important than cosmic-ray heating in molecular clouds, although there is substantial scatter in both.

Li, Pak Shing [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Myers, Andrew [Physics Department, University of California, Berkeley, CA 94720 (United States); McKee, Christopher F., E-mail: psli@astron.berkeley.edu, E-mail: atmyers@berkeley.edu, E-mail: cmckee@berkeley.edu [Physics Department and Astronomy Department, University of California, Berkeley, CA 94720 (United States)

2012-11-20T23:59:59.000Z

254

Wave turbulent statistics in non-weak wave turbulence  

E-Print Network [OSTI]

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

Naoto Yokoyama

2011-05-08T23:59:59.000Z

255

Characterization of Relativistic MHD Turbulence  

E-Print Network [OSTI]

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

Garrison, David

2015-01-01T23:59:59.000Z

256

Turbulent Combustion Luc Vervisch  

E-Print Network [OSTI]

;19 "Perfect" combustion modes: Fuel + Oxidizer () Products Engines, gas turbines... Laboratory experiment1 Turbulent Combustion Modeling Luc Vervisch INSA de Rouen, IUF, CORIA-CNRS Quelques problèmes rencontrés en chimie numérique : Hydrologie - Combustion - Atmosphère 16 décembre, INRIA Rocquencourt #12

Kern, Michel

257

Effect of turbulent heat transfer on continuous ingot solidification  

SciTech Connect (OSTI)

For many continuous ingot casting processes, turbulent heat transfer in the molten pool plays a critical role which, along with buoyancy and surface tension, is responsible for the quality of the end products. Based on a modified low Reynolds number K-[epsilon] two-equation closure, accounting for the phase change and mushy zone formation, the effect of turbulent heat transfer on the solidification characteristics during titanium alloy ingot casting in an electron beam melting process is investigated. The overall heat transfer rate is enhanced by turbulent transport via two sources, one through the correlated velocity and temperature fluctuations present for both single- and multi-phase flows, and the other through the correlated velocity and release of latent heat fluctuations which are unique to the flows with phase change. The roles played by both mechanisms are identified and assessed. The present turbulence model predicts that although the mushy zone defined by the mean temperature field is generally of substantial thickness as a result of the convection effect, the actual instantaneous zone thickness varies substantially due to turbulence effect. This finding is in contrast to the traditionally held viewpoint, based on the conduction analysis, of a generally thin mushy zone. The impact of turbulent heat transfer on local dendrite formation and remelting is illustrated and the issues involved in model development highlighted.

Shyy, W.; Chen, M.H. (Univ. of Florida, Gainesville, FL (United States). Dept. of Aerospace Engineering); Pang, Y.; Wei, D.Y. (GE Aircraft Engines, Engineering Materials Technology Labs., Lynn, MA (United States)); Hunter, G.B. (GE Aircraft Engines, Engineering Materials Technology Labs., Cincinnati, OH (United States))

1993-01-01T23:59:59.000Z

258

GYROKINETIC PARTICLE SIMULATION OF TURBULENT TRANSPORT IN BURNING PLASMAS  

SciTech Connect (OSTI)

The SciDAC project at the IFS advanced the state of high performance computing for turbulent structures and turbulent transport. The team project with Prof Zhihong Lin [PI] at Univ California Irvine produced new understanding of the turbulent electron transport. The simulations were performed at the Texas Advanced Computer Center TACC and the NERSC facility by Wendell Horton, Lee Leonard and the IFS Graduate Students working in that group. The research included a Validation of the electron turbulent transport code using the data from a steady state university experiment at the University of Columbia in which detailed probe measurements of the turbulence in steady state were used for wide range of temperature gradients to compare with the simulation data. These results were published in a joint paper with Texas graduate student Dr. Xiangrong Fu using the work in his PhD dissertation. X.R. Fu, W. Horton, Y. Xiao, Z. Lin, A.K. Sen and V. Sokolov, Validation of electron Temperature gradient turbulence in the Columbia Linear Machine, Phys. Plasmas 19, 032303 (2012).

Horton, Claude Wendell

2014-06-10T23:59:59.000Z

259

Generation of Geodesic Acoustic Modes in ITG turbulence  

SciTech Connect (OSTI)

The generation of geodesic acoustic modes (GAM) is studied by means of numerical simulations of a 3D fluid global model, describing flux-driven electrostatic ITG (Ion Temperature Gradient) turbulence in the core of tokamak plasmas. The model evolves the equilibrium and the perturbed fields as a whole. The coupling of poloidal harmonics induced by the curvature thus results in the presence of both turbulent and neoclassical transport effects in the system. The neoclassical thermal conductivity, which is linked to the time-independent component of the poloidal modulation of the equilibrium fields, is observed to be of the order of the turbulent one, in a system driven by strong injected heat fluxes. The frequency spectrum of the electrostatic potential fluctuations exhibits a peak near the theoretical GAM frequency. In the turbulent stationary state of the simulations a downshift of the GAM frequency is observed.

Falchetto, G. L.; Garbet, X.; Ottaviani, M. [Association EURATOM-CEA, CEA/DSM/DRFC, Centre de Cadarache, 13108 Saint Paul lez Durance (France); Smolyakov, A. [Department of Physics and Engineering Physics, University of Saskatchewan, SK (Canada)

2006-11-30T23:59:59.000Z

260

Aerodynamic interference between two Darrieus wind turbines  

SciTech Connect (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

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Wind Technologies & Evolving Opportunities (Presentation)  

SciTech Connect (OSTI)

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

Robichaud, R.

2014-07-01T23:59:59.000Z

262

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

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

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

263

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

Office of Environmental Management (EM)

20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply U.S. Offshore Wind Manufacturing and Supply Chain Development Wind Program Accomplishments...

264

Wind pro?le assessment for wind power purposes.  

E-Print Network [OSTI]

??Preliminary estimation of wind speed at the wind turbine hub height is critically important when planning new wind farms. Wind turbine power output is proportional (more)

Sointu, Iida

2014-01-01T23:59:59.000Z

265

Wind Powering America Webinar: Wind Power Economics: Past, Present...  

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

Wind Powering America Webinar: Wind Power Economics: Past, Present, and Future Trends Wind Powering America Webinar: Wind Power Economics: Past, Present, and Future Trends November...

266

Community Wind Handbook/Understand Your Wind Resource and Conduct...  

Open Energy Info (EERE)

Wind Resource and Conduct a Preliminary Estimate < Community Wind Handbook Jump to: navigation, search WIND ENERGY STAKEHOLDER ENGAGEMENT & OUTREACHCommunity Wind Handbook...

267

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

Energy Savers [EERE]

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

268

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

wind turbine components (specifically, generators, bladeschangers. Wind turbine components such as blades, towers,17%). Wind turbine component exports (towers, blades,

Wiser, Ryan

2012-01-01T23:59:59.000Z

269

Description of the Columbia Basin Wind Energy Study (CBWES)  

SciTech Connect (OSTI)

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 Energys 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

270

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

271

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

Prepared for the Utility Wind Integration Group. Arlington,Arizona Public Service Wind Integration Cost Impact Study.an Order Revising the Wind Integration Rate for Wind Powered

Wiser, Ryan

2010-01-01T23:59:59.000Z

272

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

2010. SPP WITF Wind Integration Study. Little Rock,an Order Revising the Wind Integration Rate for Wind PoweredPacifiCorp. 2010. 2010 Wind Integration Study. Portland,

Wiser, Ryan

2012-01-01T23:59:59.000Z

273

Wind Climatology Literature Review Jake Crouch October 12, 2010  

E-Print Network [OSTI]

Wind Climatology Literature Review Jake Crouch ­ October 12, 2010 The National Centers and climate forecast models and to monitor atmospheric phenomenon such as atmospheric winds, temperature dataset, including atmospheric winds, and set a precedent for using the dataset in a climate monitoring

274

SUBMITTED TO GRL 1 Thermal Anisotropies in the Solar Wind  

E-Print Network [OSTI]

SUBMITTED TO GRL 1 E Thermal Anisotropies in the Solar Wind: vidence of Heating by Interstellar cyclotron instabilit s generated by newly created pickup ions and heats the thermal solar wind protons TO GRL 2 T Introduction he thermal anisotropy of the solar wind is the ratio between the temperatures p

Richardson, John

275

Wind Power  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched FerromagnetismWaste and MaterialsWenjun DengWISPWind Industry Soars to New1Wind Power

276

Wind Power  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert SouthwestTechnologies | Blandine Jerome Careers at WIPPCompletes aboutWind Energy

277

Nonextensive statistical dynamics applied to wall turbulence  

E-Print Network [OSTI]

We apply a formalism of nonextensive statistical mechanics to experimental wall turbulence data, for the first time to our knowledge. Wind tunnel data for velocity differences a streamwise distance $r$ apart are compared to the prediction from theory as developed by Beck. The simplest theory, in which all free parameters are removed, is found to reproduce statistics for the wall-normal velocity component remarkably well, even for $r$ well beyond the corresponding integral scale, while the corresponding description of the streamwise velocity fluctuations is reasonable at separations below the integral scale. A least-squares 2-parameter fit is performed, and the dependence of the optimum parameter values on wall separation and $r$ is analysed. Both parameters are found to be approximately independent of wall-separation in the logarithmic sub-layer.

Simen Ellingsen; Per-ge Krogstad

2014-02-10T23:59:59.000Z

278

LES of the adverse-pressure gradient turbulent boundary layer M. Inoue a,  

E-Print Network [OSTI]

at the University of Melbourne wind tunnel where a plate section with zero pressure gradient is followed by section accurate simulations, for example, of separated flow on the wings of airplanes or for flow through turbine such as the amplified wake of the mean velocity profile and the increasing turbulence intensity in the outer region

Marusic, Ivan

279

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

SciTech Connect (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

280

Phenomenology for the decay of energy-containing eddies in homogeneous MHD turbulence  

E-Print Network [OSTI]

Phenomenology for the decay of energy-containing eddies in homogeneous MHD turbulence Murshed of simple, one-point phenomenological models for the decay of energy-containing eddies phenomenology has been previously verified against experiments in wind tunnels, and certain experimentally

Oughton, Sean

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Reynolds Number Invariance of the Structure Inclination Angle in Wall Turbulence Ivan Marusic*  

E-Print Network [OSTI]

Reynolds Number Invariance of the Structure Inclination Angle in Wall Turbulence Ivan Marusic using hot-film and hot-wire anemometry in a wind tunnel facility, and sonic anemometers and a purpose has not been available before. Structure inclination angles are inferred from the cross correlation

Marusic, Ivan

282

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

E-Print Network [OSTI]

The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the Solar Wind C02101 (2010)], we have incorporated in the heating model the energy cascade rate based on Iroshnikov scale. Since in steady state, the heating rate is essentially the same as the energy cascade rate

Ng, Chung-Sang

283

Turbulent Reconnection and Its Implications  

E-Print Network [OSTI]

Magnetic reconnection is a process of magnetic field topology change, which is one of the most fundamental processes in magnetized plasmas. In most astrophysical environments the Reynolds numbers are large and therefore the transition to turbulence is inevitable. This turbulence must be taken into account for any theory of magnetic reconnection, since the initially laminar configurations can transit to the turbulence state, what is demonstrated by 3D high resolution numerical simulations. We discuss ideas of how turbulence can modify reconnection with the focus on the Lazarian & Vishniac (1999) reconnection model and present numerical evidence supporting the model and demonstrate that it is closely connected to the concept of Richardson diffusion and compatible with the Lagrangian dynamics of magnetized fluids. We point out that the Generalized Ohm's Law, that accounts for turbulent motion, predicts the subdominance of the microphysical plasma effects for a realistically turbulent media. We show that on o...

Lazarian, Alex; Vishniac, Ethan T; Kowal, Grzegorz

2015-01-01T23:59:59.000Z

284

Transition to turbulence in ferrofluids  

E-Print Network [OSTI]

It is known that in classical fluids turbulence typically occurs at high Reynolds numbers. But can turbulence occur at low Reynolds numbers? Here we investigate the transition to turbulence in the classic Taylor-Couette system in which the rotating fluids are manufactured ferrofluids with magnetized nanoparticles embedded in liquid carriers. We find that, in the presence of a magnetic field turbulence can occur at Reynolds numbers that are at least one order of magnitude smaller than those in conventional fluids. This is established by extensive computational ferrohydrodynamics through a detailed bifurcation analysis and characterization of behaviors of physical quantities such as the energy, the wave number, and the angular momentum through the bifurcations. A striking finding is that, as the magnetic field is increased, the onset of turbulence can be determined accurately and reliably. Our results imply that experimental investigation of turbulence can be greatly facilitated by using ferrofluids, opening up...

Altmeyer, Sebastian; Lai, Ying-Cheng

2015-01-01T23:59:59.000Z

285

Turbulence in Atomic Hydrogen  

E-Print Network [OSTI]

Understanding the properties of interstellar turbulence is a great intellectual challenge and the urge to solve this problem is partially motivated by a necessity to explain the star formation mystery. This review deals with a recently suggested inversion technique as applied to atomic hydrogen. This technique allows to determine 3D turbulence statistics through the variations of 21 cm intensity. We claim that a radio interferometer is an ideal tool for such a study as its visibility function is directly related to the statistics of galactic HI. Next, we show how galactic rotation curve can be used to study the turbulence slice by slice and relate the statistics given in galactic coordinates and in the velocity space. The application of the technique to HI data reveals a shallow spectrum of the underlying HI density that is not compatible with a naive Kolmogorov picture. We show that the random density corresponding to the found spectrum tends to form low contrast filaments that are elongated towards the observer.

A. Lazarian

1998-04-02T23:59:59.000Z

286

Scrape-off layer tokamak plasma turbulence  

SciTech Connect (OSTI)

Two-dimensional (2D) interchange turbulence in the scrape-off layer of tokamak plasmas and their subsequent contribution to anomalous plasma transport has been studied in recent years using electron continuity, current balance, and electron energy equations. In this paper, numerically it is demonstrated that the inclusion of ion energy equation in the simulation changes the nature of plasma turbulence. Finite ion temperature reduces floating potential by about 15% compared with the cold ion temperature approximation and also reduces the radial electric field. Rotation of plasma blobs at an angular velocity about 1.5 Multiplication-Sign 10{sup 5} rad/s has been observed. It is found that blob rotation keeps plasma blob charge separation at an angular position with respect to the vertical direction that gives a generation of radial electric field. Plasma blobs with high electron temperature gradients can align the charge separation almost in the radial direction. Influence of high ion temperature and its gradient has been presented.

Bisai, N.; Singh, R.; Kaw, P. K. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

2012-05-15T23:59:59.000Z

287

Wave turbulence revisited: Where does the energy flow?  

E-Print Network [OSTI]

Turbulence in a system of nonlinearly interacting waves is referred to as wave turbulence. It has been known since seminal work by Kolmogorov, that turbulent dynamics is controlled by a directional energy flux through the wavelength scales. We demonstrate that an energy cascade in wave turbulence can be bi-directional, that is, can simultaneously flow towards large and small wavelength scales from the pumping scales at which it is injected. This observation is in sharp contrast to existing experiments and wave turbulence theory where the energy flux only flows in one direction. We demonstrate that the bi-directional energy cascade changes the energy budget in the system and leads to formation of large-scale, large-amplitude waves similar to oceanic rogue waves. To study surface wave turbulence, we took advantage of capillary waves on a free, weakly charged surface of superfluid helium He-II at temperature 1.7K. Although He-II demonstrates non-classical thermomechanical effects and quantized vorticity, waves on its surface are identical to those on a classical Newtonian fluid with extremely low viscosity. The possibility of directly driving a charged surface by an oscillating electric field and the low viscosity of He-II have allowed us to isolate the surface dynamics and study nonlinear surface waves in a range of frequencies much wider than in experiments with classical fluids.

L. V. Abdurakhimov; I. A. Remizov; A. A. Levchenko; G. V. Kolmakov; Y. V. Lvov

2014-04-03T23:59:59.000Z

288

Protostellar outflow-driven turbulence  

E-Print Network [OSTI]

Protostellar outflows crisscross the regions of star cluster formation, stirring turbulence and altering the evolution of the forming cluster. We model the stirring of turbulent motions by protostellar outflows, building on an observation that the scaling law of supersonic turbulence implies a momentum cascade analogous to the energy cascade in Kolmogorov turbulence. We then generalize this model to account for a diversity of outflow strengths, and for outflow collimation, both of which enhance turbulence. For a single value of its coupling coefficient the model is consistent with turbulence simulations by Li & Nakamura and, plausibly, with observations of the NGC 1333 cluster-forming region. Outflow-driven turbulence is strong enough to stall collapse in cluster-forming regions for several crossing times, relieving the mismatch between star formation and turbulent decay rates. The predicted line-width-size scaling implies radial density indices between -1 and -2 for regions supported by outflow-driven turbulence, with a tendency for steeper profiles in regions that are more massive or have higher column densities.

Christopher D. Matzner

2007-01-01T23:59:59.000Z

289

Wind Power Today  

SciTech Connect (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

2006-05-01T23:59:59.000Z

290

Wind Power Today  

SciTech Connect (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

291

Commonwealth Wind Incentive Program Micro Wind Initiative  

Broader source: Energy.gov [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...

292

Wind energy bibliography  

SciTech Connect (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

293

Wind for Schools (Poster)  

SciTech Connect (OSTI)

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

294

Temporal and Spatial Turbulent Spectra of MHD Plasma and an Observation of Variance Anisotropy  

E-Print Network [OSTI]

The nature of MHD turbulence is analyzed through both temporal and spatial magnetic fluctuation spectra. A magnetically turbulent plasma is produced in the MHD wind-tunnel configuration of the Swarthmore Spheromak Experiment (SSX). The power of magnetic fluctuations is projected into directions perpendicular and parallel to a local mean field; the ratio of these quantities shows the presence of variance anisotropy which varies as a function of frequency. Comparison amongst magnetic, velocity, and density spectra are also made, demonstrating that the energy of the turbulence observed is primarily seeded by magnetic fields created during plasma production. Direct spatial spectra are constructed using multi-channel diagnostics and are used to compare to frequency spectra converted to spatial scales using the Taylor Hypothesis. Evidence for the observation of dissipation due to ion inertial length scale physics is also discussed as well as the role laboratory experiment can play in understanding turbulence typica...

Schaffner, D A; Lukin, V S

2014-01-01T23:59:59.000Z

295

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

SciTech Connect (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 Alfvn 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 Alfvn 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 Alfvn wave generated nonlinearly by a collision between counterpropagating Alfvn waves.

Drake, D. J. [Department of Physics, Astronomy, and Geosciences, Valdosta State University, Valdosta, Georgia 31698 (United States)] [Department of Physics, Astronomy, and Geosciences, Valdosta State University, Valdosta, Georgia 31698 (United States); Schroeder, J. W. R.; Howes, G. G.; Kletzing, C. A.; Skiff, F. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)] [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Carter, T. A.; Auerbach, D. W. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States)] [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States)

2013-07-15T23:59:59.000Z

296

Advanced Computational Methods for Turbulence and Combustion...  

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

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

297

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

298

Turbulent heat transfer in parallel flow boundary layers with streamwise step changes in surface conditions  

SciTech Connect (OSTI)

This paper examines the convective heat/mass transfer behavior of a turbulent boundary layer with parallel streamlines. The most notable example of such flow is an atmospheric boundary layer with a steady mean wind in the absence of topography. The classic, two-dimensional problem involves the surface boundary condition of a finite-length step change in temperature/concentration in the streamwise direction of an atmospheric flow. In the literature on geophysical evapotranspiration, this problem is known as Sutton's problem (cf. Sutton, 1934, and Brutsaert, 1984). This flow situation is equally applicable to heat/mass transfer in solar ponds, ground solar collectors, and heated roadways, as examples. The present note revisits the Sutton problem, with the can Driest eddy diffusivity model, and expands the types of boundary conditions that are examined to include surface changes in temperature/concentration and fluxes. The parallel streamline condition allows for Graetz-type solutions, with boundary conditions at the surface and in the far flow field. The predicted results are presented as a series of power law correlations of the relevant nondimensional parameters.

Lindberg, W.R.; Lee, R.C.; Smathers, L.B. (Univ. of Wyoming, Laramie (United States))

1989-11-01T23:59:59.000Z

299

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

SciTech Connect (OSTI)

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

Boldyrev, Stanislav; Perez, Jean Carlos

2013-11-29T23:59:59.000Z

300

Module Handbook Specialisation Wind Energy  

E-Print Network [OSTI]

of Wind Turbines Module name: Wind potential, Aerodynamics & Loading of Wind Turbines Section Classes Evaluation of Wind Energy Potential Wind turbine Aerodynamics Static and dynamic Loading of Wind turbines Wind turbine Aerodynamics Static and dynamic Loading of Wind turbines Credit points 8 CP

Habel, Annegret

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Advances in compressible turbulent mixing  

SciTech Connect (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

302

Observations of Edge Turbulence  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the ContributionsArmsSpeedingSpeedingUnder Well-ControlledObservation ofofEdge Turbulence

303

Radiosonde measurements of turbulence  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, and 323Program2 RadiometerTurbulence detection on

304

Turbulence Effects at Small Scales  

E-Print Network [OSTI]

It is most natural to assume that mysterious Small Ionized and Neutral Structures (SINS) indiffuse ISM arise from turbulence. There are two obvious problem with such an explanation, however. First of all, it is generally believed that at the small scales turbulence should be damped. Second, turbulence with Kolmogorov spectrum cannot be the responsible for the SINS. We consider, however, effects, that provide spectral index flatter than the Kolmogorov one and allow action at very small scales. These are the shocks that arise in high Mach number turbulence and transfer of energy to small scales by instabilities in cosmic rays. Our examples indicate that the origin of SINS may be discovered through systematic studies of astrophysical turbulence.

A. Beresnyak; A. Lazarian

2006-10-26T23:59:59.000Z

305

Wind Resource Assessment in Europe Using Emergy  

E-Print Network [OSTI]

mance characteristics of wind generator. The wind speed atcharacteristics of the wind generator. When wind speed is

Paudel, Subodh; Santarelli, Massimo; Martin, Viktoria; Lacarriere, Bruno; Le Corre, Olivier

2014-01-01T23:59:59.000Z

306

Guide to Using the WIND Toolkit Validation Code  

SciTech Connect (OSTI)

In response to the U.S. Department of Energy's goal of using 20% wind energy by 2030, the Wind Integration National Dataset (WIND) Toolkit was created to provide information on wind speed, wind direction, temperature, surface air pressure, and air density on more than 126,000 locations across the United States from 2007 to 2013. The numerical weather prediction model output, gridded at 2-km and at a 5-minute resolution, was further converted to detail the wind power production time series of existing and potential wind facility sites. For users of the dataset it is important that the information presented in the WIND Toolkit is accurate and that errors are known, as then corrective steps can be taken. Therefore, we provide validation code written in R that will be made public to provide users with tools to validate data of their own locations. Validation is based on statistical analyses of wind speed, using error metrics such as bias, root-mean-square error, centered root-mean-square error, mean absolute error, and percent error. Plots of diurnal cycles, annual cycles, wind roses, histograms of wind speed, and quantile-quantile plots are created to visualize how well observational data compares to model data. Ideally, validation will confirm beneficial locations to utilize wind energy and encourage regional wind integration studies using the WIND Toolkit.

Lieberman-Cribbin, W.; Draxl, C.; Clifton, A.

2014-12-01T23:59:59.000Z

307

Howard County- Wind Ordinance  

Broader source: Energy.gov [DOE]

This ordinance sets up provisions for allowing small wind energy systems in various zoning districts.

308

Control strategy for variable-speed, stall-regulated wind turbines  

SciTech Connect (OSTI)

A variable-speed, constant-pitch wind turbine was investigated to evaluate the feasibility of constraining its rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. A computational model was developed, and simulations were conducted of operation in high turbulent winds. Results indicated that rotor speed and power output were well regulated. 7 refs., 7 figs.

Muljadi, E.; Pierce, K.; Migliore, P.

1998-04-01T23:59:59.000Z

309

Analysis of the Effect of Geometry Generated Turbulence on HCCI Combustion by Multi-Zone Modeling  

SciTech Connect (OSTI)

This paper illustrates the applicability of a sequential fluid mechanics, multi-zone chemical kinetics model to analyze HCCI experimental data for two combustion chamber geometries with different levels of turbulence: a low turbulence disc geometry (flat top piston), and a high turbulence square geometry (piston with a square bowl). The model uses a fluid mechanics code to determine temperature histories in the engine as a function of crank angle. These temperature histories are then fed into a chemical kinetic solver, which determines combustion characteristics for a relatively small number of zones (40). The model makes the assumption that there is no direct linking between turbulence and combustion. The results show that the multi-zone model yields good results for both the disc and the square geometries. The model makes good predictions of pressure traces and heat release rates. The experimental results indicate that the high turbulence square geometry has longer burn duration than the low turbulence disc geometry. This difference can be explained by the sequential multi-zone model, which indicates that the cylinder with the square bowl has a thicker boundary layer that results in a broader temperature distribution. This broader temperature distribution tends to lengthen the combustion, as cold mass within the cylinder takes longer to reach ignition temperature when compressed by the expansion of the first burned gases. The multi-zone model, which makes the basic assumption that HCCI combustion is controlled by chemical kinetics, is therefore capable of explaining the experimental results obtained for different levels of turbulence, without considering a direct interaction between turbulence and combustion. A direct connection between turbulence and HCCI combustion may still exists, but it seems to play a relatively minor role in determining burn duration at the conditions analyzed in this paper.

Aceves, S M; Flowers, D L; Martinez-Frias, J; Espinosa-Loza, F; Christensen, M; Johansson, B; Hessel, R P

2004-12-13T23:59:59.000Z

310

SPH compressible turbulence  

E-Print Network [OSTI]

In this paper an SPH version of the alpha turbulence model devised by Holm and his colleagues is formulated for compressible flow with a resolution that varies in space and time. The alpha model involves two velocity fields. One velocity field is obtained from the momentum equation, the other by averaging this velocity field as in the version of SPH called XSPH. The particles (fluid elements) are moved with the averaged velocity. In analogy to the continuum alpha model we obtain a particle Lagrangian from which the SPH alpha equations can be derived. The system satisfies a discrete Kelvin circulation theorem identical to that obtained with no velocity averaging. In addition, the energy, linear and angular momentum are conserved. We show that the continuum equivalent of the SPH equations are identical to the continuum alpha model, and we conjecture that they will have the same desirable features of the continuum modelincluding the reduction of energy in the high wave number modes even when the dissipation is zero. Regardless of issues concerning turbulence modelling, the SPH alpha model is a powerful extension of the XSPH algorithm which reduces disorder at short length scales and retains the constants of the motion. The SPH alpha model is simple to implement.

J. J. Monaghan

2002-04-08T23:59:59.000Z

311

CFD Analysis of the Effect of Temperature and Buoyancy Due to Concrete Building Structures Based from an Integrated DEM and  

E-Print Network [OSTI]

on atmospheric temperature and the convection winds generated in the Aburra val- ley of Medelln, Colombia

Alberta, University of

312

Estimation of Wind Speed in Connection to a Wind Turbine  

E-Print Network [OSTI]

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

313

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

314

Wind Power Outlook 2004  

SciTech Connect (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

315

Wind Resource Maps (Postcard)  

SciTech Connect (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

316

Turbulence radiation interaction in Reynolds-averaged Navier-Stokes simulations of nonpremixed piloted turbulent laboratory-scale flames  

SciTech Connect (OSTI)

Numerical simulation results are presented for two axisymmetric, nonluminous turbulent piloted jet diffusion flames: Sandia Flame D (SFD) and Delft Flame III (DFIII). Turbulence is represented by a Reynolds stress transport model, while chemistry is modeled by means of steady laminar flamelets. We use the preassumed PDF approach for turbulence-chemistry interaction. A weighted sum of gray gases model is used for the gas radiative properties. The radiative transfer equation is solved using the discrete ordinates method in the conservative finite-volume formulation. The radiative loss leads to a decrease in mean temperature, but does not significantly influence the flow and mixing fields, in terms either of mean values or of rms values of fluctuations. A systematic analysis of turbulence-radiation interaction (TRI) is carried out. By considering five different TRI formulations, and comparing also with a simple optically thin model, individual TRI contributions are isolated and quantified. For both flames, effects are demonstrated of (1) influence of temperature fluctuations on the mean Planck function, (2) temperature and composition fluctuations on the mean absorption coefficient, and (3) correlation between absorption coefficient and Planck function. The strength of the last effect is stronger in DFIII than in SFD, because of stronger turbulence-chemistry interaction and lower mean temperature in DFIII. The impact of the choice of TRI model on the prediction of the temperature-sensitive minor species NO is determined in a postprocessing step with fixed flow and mixing fields. Best agreement for NO is obtained using the most complete representation of TRI. (author)

Habibi, A.; Merci, B. [Department of Flow, Heat and Combustion Mechanics, Ghent University, B-9000 Ghent (Belgium); Roekaerts, D. [Delft University of Technology, Delft (Netherlands)

2007-10-15T23:59:59.000Z

317

Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals  

SciTech Connect (OSTI)

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

Shupe, Matthew

2013-05-22T23:59:59.000Z

318

Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals  

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

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

Shupe, Matthew

319

Compound cooling flow turbulator for turbine component  

DOE Patents [OSTI]

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

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

2014-11-25T23:59:59.000Z

320

Radiation induces turbulence in particle-laden fluids  

SciTech Connect (OSTI)

When a transparent fluid laden with solid particles is subject to radiative heating, non-uniformities in particle distribution result in local fluid temperature fluctuations. Under the influence of gravity, buoyancy induces vortical fluid motion which can lead to strong preferential concentration, enhancing the local heating and more non-uniformities in particle distribution. By employing direct numerical simulations this study shows that the described feedback loop can create and sustain turbulence. The velocity and length scale of the resulting turbulence is not known a priori, and is set by balance between viscous forces and buoyancy effects. When the particle response time is comparable to a viscous time scale, introduced in our analysis, the system exhibits intense fluctuations of turbulent kinetic energy and strong preferential concentration of particles.

Zamansky, Rmi [Centre for Turbulence Research, Stanford University, Stanford, California 94305-3035 (United States); Coletti, Filippo [Mechanical Engineering, Stanford University, California 94305-3035 (United States); Massot, Marc [Centre for Turbulence Research, Stanford University, Stanford, California 94305-3035 (United States); Ecole Centrale Paris, Laboratoire EM2C - UPR CNRS 288 et Fdration de Mathmatiques - FR CNRS 3487, Grande Voie des Vignes, 92295 Chatenay-Malabry Cedex (France); Mani, Ali [Centre for Turbulence Research, Stanford University, Stanford, California 94305-3035 (United States); Mechanical Engineering, Stanford University, California 94305-3035 (United States)

2014-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

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

322

NREL: Wind Research - Boosting Wind Plant Power Output by 4%...  

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

Boosting Wind Plant Power Output by 4%-5% through Coordinated Turbine Controls July 30, 2014 Wind plant underperformance has plagued wind plant developers for years. To address...

323

Collegiate Wind Competition Engages Tomorrow's Wind Energy Innovators...  

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

Engages Tomorrow's Wind Energy Innovators Collegiate Wind Competition Engages Tomorrow's Wind Energy Innovators January 6, 2014 - 10:00am Addthis 2014 Collegiate Teams Boise State...

324

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...

325

Wave Decay in MHD Turbulence  

E-Print Network [OSTI]

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

Andrey Beresnyak; Alex Lazarian

2008-05-06T23:59:59.000Z

326

A spray-suppression model for turbulent combustion  

SciTech Connect (OSTI)

A spray-suppression model that captures the effects of liquid suppressant on a turbulent combusting flow is developed and applied to a turbulent diffusion flame with water spray suppression. The spray submodel is based on a stochastic separated flow approach that accounts for the transport and evaporation of liquid droplets. Flame extinguishment is accounted for by using a perfectly stirred reactor (PSR) submodel of turbulent combustion. PSR pre-calculations of flame extinction times are determined using CHEMKIN and are compared to local turbulent time scales of the flow to determine if local flame extinguishment has occurred. The PSR flame extinguishment and spray submodels are incorporated into Sandia's flow fire simulation code, VULCAN, and cases are run for the water spray suppression studies of McCaffrey for turbulent hydrogen-air jet diffusion flames. Predictions of flame temperature decrease and suppression efficiency are compared to experimental data as a function of water mass loading using three assumed values of drop sizes. The results show that the suppression efficiency is highly dependent on the initial droplet size for a given mass loading. A predicted optimal suppression efficiency was observed for the smallest class of droplets while the larger drops show increasing suppression efficiency with increasing mass loading for the range of mass loadings considered. Qualitative agreement to the experiment of suppression efficiency is encouraging, however quantitative agreement is limited due to the uncertainties in the boundary conditions of the experimental data for the water spray.

DESJARDIN,PAUL E.; TIESZEN,SHELDON R.; GRITZO,LOUIS A.

2000-02-14T23:59:59.000Z

327

Next-Generation Wind Technology  

Broader source: Energy.gov [DOE]

The Wind Program works with industry partners to increase the performance and reliability of next-generation wind technologies while lowering the cost of wind energy.

328

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

natural gas prices), pushed wind energy to the top of (andperformance, and price of wind energy, policy uncertainty cost, performance, and price of wind energy, some of these

Bolinger, Mark

2013-01-01T23:59:59.000Z

329

2012 Wind Technologies Market Report  

E-Print Network [OSTI]

The Effects of Integrating Wind Power on Transmission Systemat Various Levels of Wind Power Capacity Penetration 201242 6. Wind Power Price

Wiser, Ryan

2014-01-01T23:59:59.000Z

330

Wind Farms in North America  

E-Print Network [OSTI]

About Large Offshore Wind Power: Underlying Factors. EnergyOpinion on Offshore Wind Power - Interim Report. University2002) Economic Impacts of Wind Power in Kittitas County, Wa.

Hoen, Ben

2014-01-01T23:59:59.000Z

331

WIND DATA REPORT Thompson Island  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

332

WIND DATA REPORT Thompson Island  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

333

WIND DATA REPORT Presque Isle  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

334

WIND DATA REPORT Thompson Island  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

335

WIND DATA REPORT Thompson Island  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

336

WIND DATA REPORT Presque Isle  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

337

WIND DATA REPORT Thompson Island  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

338

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

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

Wiser, Ryan

2010-01-01T23:59:59.000Z

339

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network [OSTI]

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

Bolinger, Mark

2010-01-01T23:59:59.000Z

340

WIND DATA REPORT Thompson Island  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

Note: This page contains sample records for the topic "temperature turbulence wind" 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

WIND DATA REPORT FALMOUTH, MA  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

342

WIND DATA REPORT Presque Isle  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

343

WIND DATA REPORT Presque Isle  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

344

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

2010. SPP WITF Wind Integration Study. Little Rock,GE Energy. 2011a. Oahu Wind Integration Study Final Report.PacifiCorp. 2010. 2010 Wind Integration Study. Portland,

Bolinger, Mark

2013-01-01T23:59:59.000Z

345

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

wind turbine components (specifically, generators, bladeschangers. Wind turbine components such as blades, towers,Canada (8%). Wind turbine component exports (towers, blades,

Bolinger, Mark

2013-01-01T23:59:59.000Z

346

2012 Wind Technologies Market Report  

E-Print Network [OSTI]

Colorado: Xcel Energy. 2012 Wind Technologies Market ReportOperator. 2012 Wind Technologies Market Report Chadbourne &Power Company. 2012 Wind Technologies Market Report EnerNex

Wiser, Ryan

2014-01-01T23:59:59.000Z

347

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

Market Report vii potential wind energy generation withinthat nearly 8% of potential wind energy generation withinAreas, in GWh (and % of potential wind generation) Electric

Wiser, Ryan

2012-01-01T23:59:59.000Z

348

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

capacity), with 17% of all potential wind energy generationthat roughly 17% of potential wind energy generation withinexample, roughly 1% of potential wind energy output in 2009

Wiser, Ryan

2010-01-01T23:59:59.000Z

349

The influence of a magnetic field on turbulent heat transfer of a high Prandtl number fluid  

SciTech Connect (OSTI)

The influence of a transverse magnetic field on the local and average heat transfer of an electrically conducting, turbulent fluid flow with high Prandtl number was studied experimentally. The mechanism of heat transfer modification due to magnetic field is considered with aid of available numerical simulation data for turbulent flow field. The influence of the transverse magnetic field on the heat transfer was to suppress the temperature fluctuation and to steepen the mean temperature gradient in near-wall region in the direction parallel to the magnetic field. The mean temperature gradient is not influenced compared to the temperature fluctuation in the direction vertical to the magnetic field. (author)

Nakaharai, H. [Department of Advanced Energy Engineering Science, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Takeuchi, J.; Morley, N.B.; Abdou, M.A. [Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA 90095-1597 (United States); Yokomine, T. [Faculty of Energy Engineering Science, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Kunugi, T. [Department of Nuclear Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501 (Japan); Satake, S. [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

2007-10-15T23:59:59.000Z

350

Wind energy information guide  

SciTech Connect (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

351

Wind Power Career Chat  

SciTech Connect (OSTI)

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

Not Available

2011-01-01T23:59:59.000Z

352

Comparing Wind, Temperature, Pressure, and Humidity  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity Involvement and MakingYersiniae.Shewanella genus .How

353

EA-1726: Kahuku Wind Power, LLC Wind Power Generation Facility...  

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

6: Kahuku Wind Power, LLC Wind Power Generation Facility, O'ahu, HI EA-1726: Kahuku Wind Power, LLC Wind Power Generation Facility, O'ahu, HI May 3, 2010 EA-1726: Final...

354

Gyrokinetic simulations of collisionless reconnection in turbulent non-uniform plasmas  

SciTech Connect (OSTI)

We present nonlinear gyrokinetic simulations of collisionless magnetic reconnection with non-uniformities in the plasma density, the electron temperature, and the ion temperature. The density gradient can stabilize reconnection due to diamagnetic effects but destabilize driftwave modes that produce turbulence. The electron temperature gradient triggers microtearing modes that drive rapid small-scale reconnection and strong electron heat transport. The ion temperature gradient destabilizes ion temperature gradient modes that, like the driftwaves, may enhance reconnection in some cases.

Kobayashi, Sumire [Laboratoire de Physique des Plasmas, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex (France) [Laboratoire de Physique des Plasmas, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex (France); Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Rogers, Barrett N. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States)] [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Numata, Ryusuke [Graduate School of Simulation Studies, University of Hyogo, 7-1-28 Minatojima Minami-machi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)] [Graduate School of Simulation Studies, University of Hyogo, 7-1-28 Minatojima Minami-machi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)

2014-04-15T23:59:59.000Z

355

2008 Wind Energy Projects, Wind Powering America (Poster)  

SciTech Connect (OSTI)

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

Not Available

2009-01-01T23:59:59.000Z

356

Preprints, 15th Symposium on Boundary Layers and Turbulence, 15-19 July, Wageningen, The Netherlands, 133-136.  

E-Print Network [OSTI]

shown that the ABL has a complicated structure involving generally quasi-persistent, thermal. These sensors were chosen to obtain observations of the thermal, kinematic and turbulent structure in the lowest beams. The wind profiler was deployed on the bow of the Oden during the entire cruise. It provided

Persson, Ola

357

Competitive Wind Grants (Vermont)  

Broader source: Energy.gov [DOE]

The Clean Energy Development Fund Board will offer a wind grant program beginning October 1, 2013. The grant program will replace the wind incentives that were originally part of the [http:/...

358

Residential Wind Power  

E-Print Network [OSTI]

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

Willis, Gary

2011-12-16T23:59:59.000Z

359

See the Wind  

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

See the Wind Grades: 5-8 , 9-12 Topic: Wind Energy Owner: Kidwind Project This educational material is brought to you by the U.S. Department of Energy's Office of Energy Efficiency...

360

Talbot County- Wind Ordinance  

Broader source: Energy.gov [DOE]

This ordinance amends the Talbot County Code, Chapter 190, Zoning, Subdivision and Land Development, to permit small wind turbine systems with wind turbine towers not to exceed 160 feet in total...

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Wind Energy Act (Maine)  

Broader source: Energy.gov [DOE]

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...

362

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

AWEA?s Wind Energy Weekly, DOE/EPRI?s Turbine Verification10% Wind Energy Penetration New large-scale 9 wind turbineswind energy continues to decline as a result of lower wind turbine

Wiser, Ryan

2012-01-01T23:59:59.000Z

363

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

AWEAs Wind Energy Weekly, DOE/EPRIs Turbine Verification10% Wind Energy Penetration New large-scale 8 wind turbinesTurbine Market Report. Washington, D.C. : American Wind Energy

Bolinger, Mark

2013-01-01T23:59:59.000Z

364

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network [OSTI]

Prepared for the Utility Wind Integration Group. Arlington,Wind Logics, Inc. 2004. Wind Integration StudyFinal Report.EnerNex Corp. 2006. Wind Integration Study for Public

Bolinger, Mark

2010-01-01T23:59:59.000Z

365

Kent County- Wind Ordinance  

Broader source: Energy.gov [DOE]

This ordinance establishes provisions and standards for small wind energy systems in various zoning districts in Kent County, Maryland.

366

Numeric-modeling sensitivity analysis of the performance of wind turbine arrays  

SciTech Connect (OSTI)

An evaluation of the numerical model created by Lissaman for predicting the performance of wind turbine arrays has been made. Model predictions of the wake parameters have been compared with both full-scale and wind tunnel measurements. Only limited, full-scale data were available, while wind tunnel studies showed difficulties in representing real meteorological conditions. Nevertheless, several modifications and additions have been made to the model using both theoretical and empirical techniques and the new model shows good correlation with experiment. The larger wake growth rate and shorter near wake length predicted by the new model lead to reduced interference effects on downstream turbines and hence greater array efficiencies. The array model has also been re-examined and now incorporates the ability to show the effects of real meteorological conditions such as variations in wind speed and unsteady winds. The resulting computer code has been run to show the sensitivity of array performance to meteorological, machine, and array parameters. Ambient turbulence and windwise spacing are shown to dominate, while hub height ratio is seen to be relatively unimportant. Finally, a detailed analysis of the Goodnoe Hills wind farm in Washington has been made to show how power output can be expected to vary with ambient turbulence, wind speed, and wind direction.

Lissaman, P.B.S.; Gyatt, G.W.; Zalay, A.D.

1982-06-01T23:59:59.000Z

367

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

is located in Europe. In contrast, all wind power projectsin Europe. In 2009, for example, more wind power was

Wiser, Ryan

2010-01-01T23:59:59.000Z

368

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. Atmospheric and wake turbulence impacts  

E-Print Network [OSTI]

impacts on wind turbine fatigue loadings S a n g L e e National Renewable Energy Laboratory #12;NATIONAL interaction in wind turbine arrays are not well understood -Previous fatigue loads were estimated using low and surface roughness on fatigue loading are investigated -Wake turbulence effect on the downwind turbines

Firestone, Jeremy

369

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

E-Print Network [OSTI]

of Iowa, 203 Van Allen Hall, Iowa City, Iowa 52242) The interstellar medium (ISM) and solar wind-4, Rosen Centre Hotel [BI2.004] Anisotropic MHD Turbulence in the Interstellar Medium and the Solar Wind C energy spectra has been a subject of considerable debate in recent years. In the classic work

Ng, Chung-Sang

370

CONGRESSIONAL BRIEFING Offshore Wind  

E-Print Network [OSTI]

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

Firestone, Jeremy

371

Wind power outlook 2006  

SciTech Connect (OSTI)

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

anon.

2006-04-15T23:59:59.000Z

372

Wind Economic Development (Postcard)  

SciTech Connect (OSTI)

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

Not Available

2011-08-01T23:59:59.000Z

373

Wind farm electrical system  

DOE Patents [OSTI]

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

Erdman, William L.; Lettenmaier, Terry M.

2006-07-04T23:59:59.000Z

374

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

E-Print Network [OSTI]

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

Nebraska-Lincoln, University of

375

Wind: wind speed and wind power density maps at 10m and 50m above...  

Open Energy Info (EERE)

files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikSCAT SeaWinds scatterometer....

376

Wind: wind speed and wind power density GIS data at 10m and 50m...  

Open Energy Info (EERE)

files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikScat SeaWinds scatterometer....

377

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

SciTech Connect (OSTI)

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

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

2012-01-25T23:59:59.000Z

378

Introduction to statistical turbulence modelling. Overview, RWTH Aachen, 08./09.03.2010 Introduction to statistical turbulence modelling  

E-Print Network [OSTI]

transfer of Momentum Turbulent (Reynolds) stresses Heat Turbulent heat flux Mass Turbulent: Fundamental equations Averaging Flow equations Turbulence equations Part II: Characteristics, RWTH Aachen, 08.03.2010 Reynolds' experiment: Inject dye into pipe flow Observe filament at different

379

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

E-Print Network [OSTI]

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

Castillo, Davis

2011-08-08T23:59:59.000Z

380

The Internal-Collision-Induced Magnetic Reconnection and Turbulence (ICMART) Model of Gamma-Ray Bursts  

E-Print Network [OSTI]

The recent Fermi observation of GRB 080916C shows that the bright photosphere emission associated with a putative fireball is missing, which suggests a Poynting-flux-dominated outflow. We propose a model of gamma-ray burst (GRB) prompt emission in the Poynting-flux-dominated regime, namely, the Internal-Collision-induced MAgnetic Reconnection and Turbulence (ICMART) model. It is envisaged that the GRB central engine launches an intermittent, magnetically-dominated wind, and that in the GRB emission region, the ejecta is still moderately magnetized. Similar to the internal shock (IS) model, the mini-shells interact internally at the traditional internal shock radius. Most of these early collision have little energy dissipation, but serve to distort the ordered magnetic field lines. At a certain point, the distortion of magnetic field configuration reaches the critical condition to allow fast reconnection seeds to occur, which induce relativistic MHD turbulence in the interaction regions. The turbulence further...

Zhang, Bing

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Vertical axis wind turbine  

SciTech Connect (OSTI)

Wind turbines are largely divided into vertical axis wind turbines and propeller (Horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with a starting and braking control system. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotary axis by keeping the blade span-wise direction in parallel with the axis and being provided with a low speed control windmill in which the radial position of each operating piece varies with a centrifugal force produced by the rotation of the vertical rotary axis.

Kato, Y.; Seki, K.; Shimizu, Y.

1981-01-27T23:59:59.000Z

382

Vertical axis wind turbine  

SciTech Connect (OSTI)

Wind turbines are largely divided into vertical axis wind turbines and propeller (Horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with rotational speed control systems. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotating shaft by keeping the blade span-wise direction in parallel with the shaft and being provided with aerodynamic control elements operating manually or automatically to control the rotational speed of the turbine.

Kato, Y.; Seki, K.; Shimizu, Y.

1981-01-27T23:59:59.000Z

383

Wind energy applications guide  

SciTech Connect (OSTI)

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

anon.

2001-01-01T23:59:59.000Z

384

Wind Program: Wind Vision | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption byAbout PrintableBlenderWhatFellows - PastFarmWindWind PowerWind

385

Assessment of TurbulenceChemistry Interaction in Hypersonic Turbulent Boundary Layers  

E-Print Network [OSTI]

Assessment of Turbulence­Chemistry Interaction in Hypersonic Turbulent Boundary Layers L. Duan of the turbulence­chemistry interaction are performed in hypersonic turbulent boundary layers using direct numerical simulation flowfields under typical hypersonic conditions representative of blunt-body and slender- body

Martín, Pino

386

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

E-Print Network [OSTI]

Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers Lian on future air-breathing hypersonic cruise vehicles will be turbulent and chemically reacting. To aid the design of such vehicles, a greater understanding of turbulent hypersonic flows is needed. Although

Martín, Pino

387

Wind energy conversion system  

DOE Patents [OSTI]

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

Longrigg, Paul (Golden, CO)

1987-01-01T23:59:59.000Z

388

Wind tower service lift  

DOE Patents [OSTI]

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

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

2011-09-13T23:59:59.000Z

389

Selected problems in turbulence theory and modeling  

E-Print Network [OSTI]

Three different topics of turbulence research that cover modeling, theory and model computation categories are selected and studied in depth. In the first topic, "velocity gradient dynamics in turbulence" (modeling), the Lagrangian linear diffusion...

Jeong, Eun-Hwan

2004-09-30T23:59:59.000Z

390

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

SciTech Connect (OSTI)

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

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

2011-10-01T23:59:59.000Z

391

the risk issue of wind measurement for wind turbine operation  

E-Print Network [OSTI]

Sciences, National Taiwan University #12;outline Wind measurement in meteorology and wind farm design-related issues on wind turbine operation 3/31/2011 2 #12;WIND MEASUREMENT IN METEOROLOGY & WIND FARM DESIGN 3.brainybetty.com 11 wind farm at ChangHwa Coastal Industrial Park 70m wind tower 70m 50m 30m 10m #12;1 2 3 4 5 1 (70M

Leu, Tzong-Shyng "Jeremy"

392

Turbulence and Magnetic Fields in Clouds  

E-Print Network [OSTI]

We discuss several categories of models which may explain the IMF, including the possible role of turbulence and magnetic fields.

Shantanu Basu

2004-11-15T23:59:59.000Z

393

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. Transitions are strongly enhanced by those Fourier modes in the turbulence which are approximately the same as the splitting between neutrino eigenvalues. We also find a suppression of transitions due to 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

2014-04-15T23:59:59.000Z

394

Solar-wind minor ions: recent observations  

SciTech Connect (OSTI)

During the years following the Solar Wind Four Conference at Burghausen our knowledge of the solar wind ion composition and dynamics has grown. There have been some surprises, and our understanding of the evolution of the solar wind has been improved. Systematic studies have shown that the minor ions generally travel with a common bulk speed and have temperatures roughly proportional to their masses. It has been determined that the /sup 3/He/sup + +/ content varies greatly; /sup 3/He/sup + +///sup 4/He/sup + +/ ranges from as high as 10/sup 2/ values to below 2 x 10/sup -4/. In some solar wind flows which can be related to energetic coronal events, the minor ions are found in unusual ionization states containing Fe/sup 16 +/ as a prominent ion, showing that the states were formed at unusually high temperatures. Unexpectedly, in a few flows substantial quantities of /sup 4/He/sup +/ have been detected, sometimes with ions identifiable as O/sup 2 +/ and O/sup 3 +/. Surprisingly, in some of these examples the ionization state is mixed showing that part of the plasma escaped the corona without attaining the usual million-degree temperatures while other parts were heated more nearly in the normal manner. Additionally, detailed studies of the minor ions have increased our understanding of the coronal expansion. For example, such studies have contributed to identifying near equatorial coronal streamers as the source of solar wind flows between high speed streams.

Bame, S.J.

1982-01-01T23:59:59.000Z

395

NREL: Wind Research - WindPACT  

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

the cost of wind energy Determine probable size ranges of advanced utility-scale turbines over the next decade for U.S. application Evaluate advanced concepts that are...

396

TURBULENCE IN SUPERSONIC AND HYPERSONIC BOUNDARY LAYERS  

E-Print Network [OSTI]

TURBULENCE IN SUPERSONIC AND HYPERSONIC BOUNDARY LAYERS Alexander J. Smits and M. Pino Martin in supersonic and hypersonic flow where the effects of compressibility have a direct influence on the turbulence. Experimental and DNS results are presented and compared. Key words: Turbulence, supersonic, hypersonic, shocks

Martín, Pino

397

Numerical Study of a Turbulent Hydraulic Jump  

E-Print Network [OSTI]

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

Zhao, Qun

398

Large-Eddy Simulation of Wind-Plant Aerodynamics: Preprint  

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

399

Colliding Winds in Low-Mass Binary Star Systems: wind interactions and implications for habitable planets  

E-Print Network [OSTI]

Context. In binary star systems, the winds from the two components impact each other, leading to strong shocks and regions of enhanced density and temperature. Potentially habitable circumbinary planets must continually be exposed to these interactions regions. Aims. We study, for the first time, the interactions between winds from low-mass stars in a binary system, to show the wind conditions seen by potentially habitable circumbinary planets. Methods. We use the advanced 3D numerical hydrodynamic code Nurgush to model the wind interactions of two identical winds from two solar mass stars with circular orbits and a binary separation of 0.5 AU. As input into this model, we use a 1D hydrodynamic simulation of the solar wind, run using the Versatile Advection Code. We derive the locations of stable and habitable orbits in this system to explore what wind conditions potentially habitable planets will be exposed to during their orbits. Results. Our wind interaction simulations result in the formation of two stron...

Johnstone, C P; Pilat-Lohinger, E; Bisikalo, D; Gdel, M; Eggl, S

2015-01-01T23:59:59.000Z

400

Turbulence transport with nonlocal interactions  

SciTech Connect (OSTI)

This preliminary report describes a variety of issues in turbulence transport analysis with particular emphasis on closure procedures that are nonlocal in wave-number and/or physical space. Anomalous behavior of the transport equations for large scale parts of the turbulence spectrum are resolved by including the physical space nonlocal interactions. Direct and reverse cascade processes in wave-number space are given a much richer potential for realistic description by the nonlocal formulations. The discussion also describes issues, many still not resolved, regarding new classes of self-similar form functions.

Linn, R.R.; Clark, T.T.; Harlow, F.H.; Turner, L.

1998-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Refined similarity hypotheses in shell models of turbulence  

E-Print Network [OSTI]

A major challenge in turbulence research is to understand from first principles the origin of anomalous scaling of the velocity fluctuations in high-Reynolds-number turbulent flows. One important idea was proposed by Kolmogorov [J. Fluid Mech. {\\bf 13}, 82 (1962)], which attributes the anomaly to the variations of the locally averaged energy dissipation rate. Kraichnan later pointed out [J. Fluid Mech. {\\bf 62}, 305 (1973)] that the locally averaged energy dissipation rate is not an inertial-range quantity and a proper inertial-range quantity would be the local energy transfer rate. As a result, Kraichnan's idea attributes the anomaly to the variations of the local energy transfer rate. These ideas, generally known as refined similarity hypotheses, can also be extended to study the anomalous scaling of fluctuations of an active scalar, like the temperature in turbulent convection. In this paper, we examine the validity of these refined similarity hypotheses and their extensions to an active scalar in shell models of turbulence. We find that Kraichnan's refined similarity hypothesis and its extension are valid.

Emily S. C. Ching; H. Guo; T. S. Lo

2008-04-16T23:59:59.000Z

402

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

E-Print Network [OSTI]

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

Stevens, Richard J A M; Meneveau, Charles

2014-01-01T23:59:59.000Z

403

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

E-Print Network [OSTI]

In this paper we have estimated typical anomalous viscosity, resistivity, and thermal difffusivity of the solar wind plasma. Since the solar wind is collsionless plasma, we have assumed that the dissipation in the solar wind occurs at proton gyro radius through wave-particle interactions. Using this dissipation length-scale and the dissipation rates calculated using MHD turbulence phenomenology [Verma et al., 1995a], we estimate the viscosity and proton thermal diffusivity. The resistivity and electrons thermal diffusivity have also been estimated. We find that all our transport quantities are several orders of magnitude higher than those calculated earlier using classical transport theories of Braginskii. In this paper we have also estimated the eddy turbulent viscosity. 1 1

Mahendra K. Verma

2008-01-01T23:59:59.000Z

404

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

E-Print Network [OSTI]

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

Mahendra K. Verma

1995-09-05T23:59:59.000Z

405

Wind energy conversion system  

SciTech Connect (OSTI)

This patent describes a wind energy conversion system comprising: a propeller rotatable by force of wind; a generator of electricity mechanically coupled to the propeller for converting power of the wind to electric power for use by an electric load; means coupled between the generator and the electric load for varying the electric power drawn by the electric load to alter the electric loading of the generator; means for electro-optically sensing the speed of the wind at a location upwind from the propeller; and means coupled between the sensing means and the power varying means for operating the power varying means to adjust the electric load of the generator in accordance with a sensed value of wind speed to thereby obtain a desired ratio of wind speed to the speed of a tip of a blade of the propeller.

Longrigg, P.

1987-03-17T23:59:59.000Z

406

WINDExchange Offshore Wind Webinar: Transmission Planning and...  

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

Offshore Wind Webinar: Transmission Planning and Interconnection for Offshore Wind WINDExchange Offshore Wind Webinar: Transmission Planning and Interconnection for Offshore Wind...

407

wind_guidance  

Broader source: Energy.gov [DOE]

Guidance to Accompany Non-Availability Waiver of the Recovery Act Buy American Provisions for 5kW and 50kW Wind Turbines

408

Barstow Wind Turbine Project  

Broader source: Energy.gov [DOE]

Presentation covers the Barstow Wind Turbine project for the Federal Utility Partnership Working Group (FUPWG) meeting, held on November 18-19, 2009.

409

Vertical axis wind turbines  

DOE Patents [OSTI]

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

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

2011-03-08T23:59:59.000Z

410

Wind Wave Float  

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

Weinstein Principle Power, Inc. aweinstein@principlepowerinc.com November 1, 2011 2 | Wind and Water Power Program eere.energy.gov Purpose, Objectives, & Integration Project...

411

Talkin Bout Wind Generation  

Broader source: Energy.gov [DOE]

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

412

Wind Engineering & Natural Disaster Mitigation  

E-Print Network [OSTI]

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

Denham, Graham

413

Wind Energy and Spatial Technology  

E-Print Network [OSTI]

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

Schweik, Charles M.

414

Proceedings Nordic Wind Power Conference  

E-Print Network [OSTI]

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

415

Economics of Online Structural Health Monitoring of Wind Turbines: Cost Benefit Analysis  

E-Print Network [OSTI]

Economics of Online Structural Health Monitoring of Wind Turbines: Cost Benefit Analysis Jeremy Van monitoring (OSHM) and condition-based maintenance (CBM) of wind turbine blades has the potential to reduce O cost of energy (LCOE) [1]. The costs required to keep wind turbines working in extreme temperatures

McCalley, James D.

416

Climatology of katabatic winds in the McMurdo dry valleys, southern Victoria Land, Antarctica  

E-Print Network [OSTI]

Climatology of katabatic winds in the McMurdo dry valleys, southern Victoria Land, Antarctica of katabatic winds largely controls winter (June to August) temperatures, increasing 1°C per 1% increase of katabatic winds in the McMurdo dry valleys, southern Victoria Land, Antarctica, J. Geophys. Res., 109, D

Fountain, Andrew G.

417

The r-Process in Supersonic Neutrino-Driven Winds: The Roll of Wind Termination Shock  

E-Print Network [OSTI]

Recent hydrodynamic studies of core-collapse supernovae imply that the neutrino-heated ejecta from a nascent neutron star develops to supersonic outflows. These supersonic winds are influenced by the reverse shock from the preceding supernova ejecta, forming the wind termination shock. We investigate the effects of the termination shock in neutrino-driven winds and its roll on the r-process. Supersonic outflows are calculated with a semi-analytic neutrino-driven wind model. Subsequent termination-shocked, subsonic outflows are obtained by applying the Rankine-Hugoniot relations. We find a couple of effects that can be relevant for the r-process. First is the sudden slowdown of the temperature decrease by the wind termination. Second is the entropy jump by termination-shock heating, up to several 100NAk. Nucleosynthesis calculations in the obtained winds are performed to examine these effects on the r-process. We find that 1) the slowdown of the temperature decrease plays a decisive roll to determine the r-process abundance curves. This is due to the strong dependences of the nucleosynthetic path on the temperature during the r-process freezeout phase. Our results suggest that only the termination-shocked winds with relatively small shock radii (~500km) are relevant for the bulk of the solar r-process abundances (A~100-180). The heaviest part in the solar r-process curve (A~180-200), however, can be reproduced both in shocked and unshocked winds. These results may help to constrain the mass range of supernova progenitors relevant for the r-process. We find, on the other hand, 2) negligible roles of the entropy jump on the r-process. This is a consequence that the sizable entropy increase takes place only at a large shock radius (~10,000km) where the r-process has already ceased.

Takami Kuroda; Shinya Wanajo; Ken'ichi Nomoto

2007-09-17T23:59:59.000Z

418

Wind Power Today, 2010, Wind and Water Power Program (WWPP)  

SciTech Connect (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 Water Power Program.

Not Available

2010-05-01T23:59:59.000Z

419

American Wind Energy Association Wind Energy Finance and Investment...  

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

Wind Energy Finance and Investment Seminar American Wind Energy Association Wind Energy Finance and Investment Seminar October 20, 2014 8:00AM EDT to October 21, 2014 5:00PM EDT...

420

Wind Powering America's Wind for Schools Team Honored with Wirth...  

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

America's Wind for Schools Team Honored with Wirth Chair Award Wind Powering America's Wind for Schools Team Honored with Wirth Chair Award May 1, 2012 - 2:46pm Addthis This is an...

Note: This page contains sample records for the topic "temperature turbulence wind" 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

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

Office of Environmental Management (EM)

: Increasing Wind Energy's Contribution to U.S. Electricity Supply 20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply Here you will find the...

422

LARGE SCALE WIND CLIMATOLOGICAL EXAMINATIONS OF WIND ENERGY UTILIZATION  

E-Print Network [OSTI]

The aim of this article is to describe the particular field of climatology which analyzes air movement characteristics regarding utilization of wind for energy generation. The article describes features of wind energy potential available in Hungary compared to wind conditions in other areas of the northern quarter sphere in order to assist the wind energy use development in Hungary. Information on wind climate gives a solid basis for financial and economic decisions of stakeholders in the field of wind energy utilization.

Andrea Kircsi

423

Investigation of Flow, Turbulence, and Dispersion within Built Environments  

E-Print Network [OSTI]

fluctuation and vertical mean wind speed reduced finefluctuation ( ? w ) and vertical mean wind speed (W) on DTFPwind speed; W -vertical mean wind speed; WD -wind direction;

Pan, Hansheng

2011-01-01T23:59:59.000Z

424

Q-Winds satellite hurricane wind retrievals and H*Wind comparisons  

E-Print Network [OSTI]

tailored to extreme wind events. Because of this and precipitation effects, scatterometers have failed/passive scatterometer retrieval algorithm designed specifically for extreme wind events, hereafter identified1 Q-Winds satellite hurricane wind retrievals and H*Wind comparisons Pet Laupattarakasem and W

Hennon, Christopher C.

425

Investigation of temperature in the stratosphere  

E-Print Network [OSTI]

of Parameters . 19 1. Horizontal temperature advection . . . . . . . 19 2. Local time rate-of- change of temperature . 26 Vertical motions . . . . 29 D. The 1"orecasting of Tempera- ture 51 E. Comparison of Thermal Winds and Wind. Shear Vectors V...!ITHOUT SMOOTHING THE HIND DATA I oc ation Date Vertical Velocity (cm/sec) Unsmoothed winds Smoothed winds (Rook Ss d d C ! (~ks, d Ss~d PGU"' 17 Jan 1$6$ 1700 GMT 'ktSI!R+ 1$ Dec I'36$ 1715 GMT. -5. 2 -1. $ 1 s7 IJSMR 18 Dec lo6$ 1800 GMT -2. 2 -1. 7...

Kays, Marvin Dale

2012-06-07T23:59:59.000Z

426

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

Office of Environmental Management (EM)

Summary) 20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply (Executive Summary) Executive summary of a report on the requirements needed...

427

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

AWEAs Wind Energy Weekly, DOE/EPRIs Turbine Verification10% Wind Energy Penetration New large-scale 10 wind turbineswind energy became more challenging, orders for new turbines

Wiser, Ryan

2010-01-01T23:59:59.000Z

428

Wind Farms in North America  

E-Print Network [OSTI]

P. and Mueller, A. (2010) Wind Farm Announcements and RuralProposed Rail Splitter Wind Farm. Prepared for Hinshaw &Economic Analysis of a Wind Farm in Nantucket Sound. Beacon

Hoen, Ben

2014-01-01T23:59:59.000Z

429

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

natural gas prices), pushed wind energy from the bottom toover the cost and price of wind energy that it receives. Asweighted-average price of wind energy in 1999 was $65/MWh (

Wiser, Ryan

2010-01-01T23:59:59.000Z

430

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network [OSTI]

natural gas prices, though the economic value of wind energyenergy and climate policy initiatives. With wind turbine pricesprices reported here would be at least $20/MWh higher without the PTC), they do not represent wind energy

Bolinger, Mark

2010-01-01T23:59:59.000Z

431

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

weighted-average price of wind energy in 1999 was roughly $reduced near-term price expectations, wind energy?s primaryelectricity prices in 2009 pushed wind energy to the top of

Wiser, Ryan

2012-01-01T23:59:59.000Z

432

Fort Carson Wind Resource Assessment  

SciTech Connect (OSTI)

This report focuses on the wind resource assessment, the estimated energy production of wind turbines, and economic potential of a wind turbine project on a ridge in the southeastern portion of the Fort Carson Army base.

Robichaud, R.

2012-10-01T23:59:59.000Z

433

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

and the drop in wind power plant installations since 2009and the drop in wind power plant installations since 2009towers used in U.S. wind power plants increases from 80% in

Bolinger, Mark

2013-01-01T23:59:59.000Z

434

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

and the drop in wind power plant installations, for example,the decrease in new wind power plant construction. A GrowingRelative Economics of Wind Power Plants Installed in Recent

Wiser, Ryan

2012-01-01T23:59:59.000Z

435

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

AWEA). 2010b. AWEA Small Wind Turbine Global Market Survey,html David, A. 2009. Wind Turbines: Industry and Tradewhich new large-scale wind turbines were installed in 2009 (

Wiser, Ryan

2010-01-01T23:59:59.000Z

436

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

ET2/TL-08-1474. May 19, 2010 Wind Technologies Market ReportAssociates. 2010. SPP WITF Wind Integration Study. Little10, 2010. David, A. 2009. Wind Turbines: Industry and Trade

Wiser, Ryan

2012-01-01T23:59:59.000Z

437

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

Associates. 2010. SPP WITF Wind Integration Study. LittlePool. David, A. 2011. U.S. Wind Turbine Trade in a Changing2011. David, A. 2010. Impact of Wind Energy Installations on

Bolinger, Mark

2013-01-01T23:59:59.000Z

438

2011 Wind Technologies Market Report  

E-Print Network [OSTI]

shows that 8.5% of potential wind energy generation withinin GWh (and as a % of potential wind generation) Electricreport also laid out a potential wind power deployment path

Bolinger, Mark

2013-01-01T23:59:59.000Z

439

NREL: Wind Research - Wind Resource Assessment  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratory | NationalJohn F. Geisz,AerialStaff Here you willWind EnergyWind

440

West Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160 East 300 South Place: SaltTroyer & AssociatesWest CentralUkinrekWest Winds Wind

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Wind Vision Wind Farm | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160 East 300 South Place:ReferenceEdit JumpWill County, Illinois:4 Sector WindOaxacaWind

442

Small Wind Information (Postcard)  

SciTech Connect (OSTI)

The U.S. Department of Energy's Wind Powering America initiative maintains a website section devoted to information about small wind turbines for homeowners, ranchers, and small businesses. This postcard is a marketing piece that stakeholders can provide to interested parties; it will guide them to this online resource.

Not Available

2011-08-01T23:59:59.000Z

443

Offshore Wind Geoff Sharples  

E-Print Network [OSTI]

Offshore Wind Geoff Sharples geoff@clearpathenergyllc.com #12;Frequently Unanswered Ques?ons · Why don't "they" build more offshore wind? · Why not make the blades bigger? · How big will turbines get? #12;Offshore Resource is Good #12

Kammen, Daniel M.

444

Carbon smackdown: wind warriors  

ScienceCinema (OSTI)

July 16. 2010 carbon smackdown summer lecture: learn how Berkeley Lab scientists are developing wind turbines to be used in an urban setting, as well as analyzing what it will take to increase the adoption of wind energy in the U.S.

Glen Dahlbacka of the Accelerator & Fusion Research Division and Ryan Wiser of the Environmental Energy Technologies Division are the speakers.

2010-09-01T23:59:59.000Z

445

Carbon smackdown: wind warriors  

SciTech Connect (OSTI)

July 16. 2010 carbon smackdown summer lecture: learn how Berkeley Lab scientists are developing wind turbines to be used in an urban setting, as well as analyzing what it will take to increase the adoption of wind energy in the U.S.

Glen Dahlbacka of the Accelerator & Fusion Research Division and Ryan Wiser of the Environmental Energy Technologies Division are the speakers.

2010-07-21T23:59:59.000Z

446

VARIABLE SPEED WIND TURBINE  

E-Print Network [OSTI]

Wind energy is currently the fastest-growing renewable source of energy in India; India is a key market for the wind industry, presenting substantial opportunities for both the international and domestic players. In India the research is carried out on wind energy utilization on big ways.There are still many unsolved challenges in expanding wind power, and there are numerous problems of interest to systems and control researchers. In this paper we study the pitch control mechanism of wind turbine. The pitch control system is one of the most widely used control techniques to regulate the output power of a wind turbine generator. The pitch angle is controlled to keep the generator power at rated power by reducing the angle of the blades. By regulating, the angle of stalling, fast torque changes from the wind will be reutilized. It also describes the design of the pitch controller and discusses the response of the pitch-controlled system to wind velocity variations. The pitch control system is found to have a large output power variation and a large settling time.

Chatinderpal Singh

447

Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer  

E-Print Network [OSTI]

coordinate and (b) wind and potential temperature at the up-coordinate and (b) wind and potential temperature at the up-Mean profiles of wind and potential temperature, turbulent

Zhou, Bowen

2012-01-01T23:59:59.000Z

448

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]

IMPROVEMENT OF THE WIND FARM MODEL FLAP FOR OFFSHORE APPLICATIONS Bernhard Lange(1), Hans 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

Heinemann, Detlev

449

Illinois Wind Workers Group  

SciTech Connect (OSTI)

The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

David G. Loomis

2012-05-28T23:59:59.000Z

450

Multiphase turbulent interstellar medium: some recent results from radio astronomy  

E-Print Network [OSTI]

The radio frequency 1.4 GHz transition of the atomic hydrogen is one of the important tracers of the diffuse neutral interstellar medium. Radio astronomical observations of this transition, using either a single dish telescope or an array interferometer, reveal different properties of the interstellar medium. Such observations are particularly useful to study the multiphase nature and turbulence in the interstellar gas. Observations with multiple radio telescopes have recently been used to study these two closely related aspects in greater detail. Using various observational techniques, the density and the velocity fluctuations in the Galactic interstellar medium was found to have a Kolmogorov-like power law power spectra. The observed power law scaling of the turbulent velocity dispersion with the length scale can be used to derive the true temperature distribution of the medium. Observations from a large ongoing atomic hydrogen absorption line survey have also been used to study the distribution of gas at d...

Roy, Nirupam

2015-01-01T23:59:59.000Z

451

Wind Wildlife Research Meeting X  

Broader source: Energy.gov [DOE]

The biennial Wind Wildlife Research Meeting provides an internationally recognized forum for researchers and wind-wildlife stakeholders to hear contributed papers, view research posters, and listen...

452

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network [OSTI]

AWEAs Wind Energy Weekly, DOE/EPRIs Turbine VerificationTurbine Global Market Study: Year Ending 2008. Washington, DC: American Wind Energy

Bolinger, Mark

2010-01-01T23:59:59.000Z

453

Wind and Solar Curtailment: Preprint  

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

Integration of Wind Power Into Power Systems as Well as on Transmission Networks for Offshore Wind Power Plants London, England October 22 - 24, 2013 Conference Paper NREL...

454

Wind Energy Resources and Technologies  

Broader source: Energy.gov [DOE]

This page provides a brief overview of wind energy resources and technologies supplemented by specific information to apply wind energy within the Federal sector.

455

Large Wind Property Tax Reduction  

Broader source: Energy.gov [DOE]

In 2001, North Dakota established property tax reductions for commercial wind turbines constructed before 2011. Originally, the law reduced the taxable value of centrally-assessed* wind turbines...

456

2010 Wind Technologies Market Report  

E-Print Network [OSTI]

wind turbine equipment-related costs are assumed to equal 85% of 2010 Wind Technologies Market Report periods to further avoid noise

Wiser, Ryan

2012-01-01T23:59:59.000Z

457

2009 Wind Technologies Market Report  

E-Print Network [OSTI]

selected wind turbine components that include towers (tradeWind turbine transactions differ in the services offered (e.g. , whether towers

Wiser, Ryan

2010-01-01T23:59:59.000Z

458

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network [OSTI]

wind turbine manufacturers: Vestas (nacelles, blades, and towersWind turbine transactions differ in the services offered (e.g. , whether towers

Bolinger, Mark

2010-01-01T23:59:59.000Z

459

Wind Events | Department of Energy  

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

Below is an industry calendar with meetings, conferences, and webinars of interest to the wind energy technology communities. IEA Wind Task 34 (WREN) Quarterly Webinar 3:...

460

Quantitative imaging of turbulent and reacting flows  

SciTech Connect (OSTI)

Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing excitation/detection strategies which provide for a quantitative measure of particular flowfield scalars. The standard camera used for the study is an intensified CCD array operated in a conventional video format. The design of the system was based on detailed modeling of signal and image transfer properties of fast UV imaging lenses, image intensifiers and CCD detector arrays. While this system is suitable for direct scalar imaging, derived quantities (e.g. temperature or velocity images) require an exceptionally wide dynamic range imaging detector. To apply these diagnostics to reacting flows also requires a very fast shuttered camera. The authors have developed and successfully tested a new type of gated low-light level detector. This system relies on fast switching of proximity focused image-diode which is direct fiber-optic coupled to a cooled CCD array. Tests on this new detector show significant improvements in detection limit, dynamic range and spatial resolution as compared to microchannel plate intensified arrays.

Paul, P.H. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature turbulence wind" 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

Measured and predicted rotor performance for the SERI advanced wind turbine blades  

SciTech Connect (OSTI)

Measured and predicted rotor performance for the SERI advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass wind farm area. Using sonic or cup anemometers, good agreement was achieved between predicted and measured power output for wind speeds up to 8 m/sec. At higher wind speeds an optimistic predicted power output and the occurrence of peak power at wind speeds lower than measurements resulted from the omission of turbulence and yaw error. In addition, accurate two-dimensional (2-D) airfoil data prior to stall and a post stall airfoil data synthesization method that reflects three-dimensional (3-D) effects were found to be essential for accurate performance prediction. 11 refs.

Tangler, J.; Smith, B.; Kelley, N.; Jager, D.

1992-02-01T23:59:59.000Z

462

Energy- and flux-budget (EFB) turbulence closure model for the stably stratified flows. Part I: Steady-state, homogeneous regimes  

E-Print Network [OSTI]

We propose a new turbulence closure model based on the budget equations for the key second moments: turbulent kinetic and potential energies: TKE and TPE (comprising the turbulent total energy: TTE = TKE + TPE) and vertical turbulent fluxes of momentum and buoyancy (proportional to potential temperature). Besides the concept of TTE, we take into account the non-gradient correction to the traditional buoyancy flux formulation. The proposed model grants the existence of turbulence at any gradient Richardson number, Ri. Instead of its critical value separating - as usually assumed - the turbulent and the laminar regimes, it reveals a transition interval, 0.11. Predictions from this model are consistent with available data from atmospheric and lab experiments, direct numerical simulation (DNS) and large-eddy simulation (LES).

S. S. Zilitinkevich; T. Elperin; N. Kleeorin; I. Rogachevskii

2007-02-19T23:59:59.000Z

463

Ris National Laboratory DTU Wind Energy Department  

E-Print Network [OSTI]

wind speed, wind direction relative to the spinner and flow inclination angle. A wind tunnel concept anemometer is a wind measurement concept in which measurements of wind speed in the flow over a wind turbine on a modified 300kW wind turbine spinner, was mounted with three 1D sonic wind speed sensors. The flow around

464

Transport enhancement and suppression in turbulent magnetic reconnection: A self-consistent turbulence model  

SciTech Connect (OSTI)

Through the enhancement of transport, turbulence is expected to contribute to the fast reconnection. However, the effects of turbulence are not so straightforward. In addition to the enhancement of transport, turbulence under some environment shows effects that suppress the transport. In the presence of turbulent cross helicity, such dynamic balance between the transport enhancement and suppression occurs. As this result of dynamic balance, the region of effective enhanced magnetic diffusivity is confined to a narrow region, leading to the fast reconnection. In order to confirm this idea, a self-consistent turbulence model for the magnetic reconnection is proposed. With the aid of numerical simulations where turbulence effects are incorporated in a consistent manner through the turbulence model, the dynamic balance in the turbulence magnetic reconnection is confirmed.

Yokoi, N. [Institute of Industrial Science, University of Tokyo, Tokyo (Japan)] [Institute of Industrial Science, University of Tokyo, Tokyo (Japan); Higashimori, K.; Hoshino, M. [Department of Earth and Planetary Science, University of Tokyo, Tokyo (Japan)] [Department of Earth and Planetary Science, University of Tokyo, Tokyo (Japan)

2013-12-15T23:59:59.000Z

465

PowerJet Wind Turbine Project  

SciTech Connect (OSTI)

PROJECT OBJECTIVE The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energyâ??s objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds. The test model will continue to operate beyond the time frame of the project, with the ultimate goal of manufacturing and marketing the PowerJet worldwide. Increased Understanding of Electronic & Mechanical Controls Integrated With Electricity Generator The PowerJet back plate begins to open as wind speed exceeds 13.5 mps. The pressure inside the turbine and the turbine rotational speed are held constant. Once the back plate has fully opened at approximately 29 mps, the controller begins pulsing back to the generator to limit the rotational speed of the turbine. At a wind speed in excess of 29 mps, the controller shorts the generator and brings the turbine to a complete stop. As the wind speed subsides, the controller releases the turbine and it resumes producing electricity. Data collection and instrumentation problems prevented identification of the exact speeds at which these events occur. However, the turbine, controller and generator survived winds in excess of 36 mps, confirming that the two over-speed controls accomplished their purpose. Technical Effectiveness & Economic Feasibility Maximum Electrical Output The output of electricity is maximized by the integration of an electronic controller and mechanical over-speed controls designed and tested during the course of this project. The output exceeds that of the PowerJetâ??s 3-bladed counterparts (see Appendix). Durability All components of the PowerJet turbine assemblyâ??including the electronic and mechanical controls designed, manufactured and field tested during the course of this projectâ??proved to be durable through severe weather conditions, with constant operation and no interruption in energy production. Low Cost Materials for the turbine, generator, tower, charge controllers and ancillary parts are available at reasonable prices. Fabrication of these parts is also readily available worldwide. The cost of assembling and installing the turbine is reduced because it has fewer parts and requires less labor to manufacture and assemble, making it competitively priced compared with turbines of similar output manufactured in the U.S. and Europe. The electronic controller is the unique part to be included in the turbine package. The controllers can be manufactured in reasonably-sized production runs to keep the cost below $250 each. The data logger and 24 sensors are for research only and will be unnecessary for the commercial product. Benefit To Public The PowerJet wind-electric system is designed for distributed wind generation in 3 and 4 class winds. This wind turbine meets DOEâ??s requirements for a quiet, durable, bird-safe turbine that eventually can be deployed as a grid-connected generator in urban and suburban settings. Results As described more fully below and illustrated in the Appendices, the goals and objectives outlined in 2060 SOPO were fully met. Electronic and mechanical controls were successfully designed, manufactured and integrated with the generator. The turbine, tower, controllers and generators operated without incident throughout the test period, surviving severe winter and summer weather conditions such as extreme temperatures, ice and sustained high winds. The electronic controls were contained in weather-proof electrical boxes and the elec

Bartlett, Raymond J

2008-11-30T23:59:59.000Z

466

Wind Energy Kit | Photosynthetic Antenna Research Center  

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

Wind Energy Kit Wind Energy Kit Wind Energy :: Kit Materials List Below is a list of the different Wind Energy kits available. For more details, download the Wind Energy Kit List....

467

Wind Energy Program: Top 10 Program Accomplishments  

Broader source: Energy.gov [DOE]

Brochure on the top accomplishments of the Wind Energy Program, including the development of large wind machines, small machines for the residential market, wind tunnel testing, computer codes for modeling wind systems, high definition wind maps, and successful collaborations.

468

Structure of atmospheric turbulence in the friction layer below 500 meters  

E-Print Network [OSTI]

aligned to an azimuth angle of 240 deg. The effect of the tower on measured wind speeds is considerable only for wind directions between 350 and 70 deg; the prevailing wind direction during this study was around ? 1 170 deg. The sensor has a speed... below about 500 m was facilitated by the fact that shearing stresses and vertical heat flux could be calculated directly from wind speed and direction~ vertical velocity, and temperature fluctuations measured nn a tower 444 m high, This eliminated...

Maas, Stephan Joseph

2012-06-07T23:59:59.000Z

469

Mimicking a turbulent signal: sequential multiaffine processes  

E-Print Network [OSTI]

An efficient method for the construction of a multiaffine process, with prescribed scaling exponents, is presented. At variance with the previous proposals, this method is sequential and therefore it is the natural candidate in numerical computations involving synthetic turbulence. The application to the realization of a realistic turbulent-like signal is discussed in detail. The method represents a first step towards the realization of a realistic spatio-temporal turbulent field.

L. Biferale; G. Boffetta; A. Celani; A. Crisanti; A. Vulpiani

1997-11-03T23:59:59.000Z

470

Utilizing Wind: Optimal Wind Farm Placement in the United States  

E-Print Network [OSTI]

Utilizing Wind: Optimal Wind Farm Placement in the United States By: Yintao Sun Advisor: Professor Acknowledgements First and foremost, I would like to thank my advisor, Professor Warren Powell, for all the help he An Introduction to Wind Energy 1 1.1 Wind, a Brief History . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Powell, Warren B.

471

Wind Energy at NREL's National Wind Technology Center  

ScienceCinema (OSTI)

It is a pure, plentiful natural resource. Right now wind is in high demand and it holds the potential to transform the way we power our homes and businesses. NREL is at the forefront of wind energy research and development. NREL's National Wind Technology Center (NWTC) is a world-class facility dedicated to accelerating and deploying wind technology.

None

2013-05-29T23:59:59.000Z

472

Wind Energy at NREL's National Wind Technology Center  

SciTech Connect (OSTI)

It is a pure, plentiful natural resource. Right now wind is in high demand and it holds the potential to transform the way we power our homes and businesses. NREL is at the forefront of wind energy research and development. NREL's National Wind Technology Center (NWTC) is a world-class facility dedicated to accelerating and deploying wind technology.

None

2010-01-01T23:59:59.000Z

473

Reference wind farm selection for regional wind power prediction models  

E-Print Network [OSTI]

1 Reference wind farm selection for regional wind power prediction models Nils Siebert George.siebert@ensmp.fr, georges.kariniotakis@ensmp.fr Abstract Short-term wind power forecasting is recognized today as a major requirement for a secure and economic integration of wind generation in power systems. This paper deals

Paris-Sud XI, Université de

474

WIND ENERGY Wind Energ. 2013; 00:112  

E-Print Network [OSTI]

WIND ENERGY Wind Energ. 2013; 00:1­12 DOI: 10.1002/we RESEARCH ARTICLE Model predictive control in wind speed, ensuring certain power gradients, with an insignificant loss in energy production rejection, model predictive control, convex optimization, wind power control, energy storage, power output

475

WIND ENERGY Wind Energ. 2013; 16:7790  

E-Print Network [OSTI]

energy industry lags far behind the wind energy industry, it has the potential to become a role player is equal to the long-term potential of onshore wind energy.1,2 Therefore, the utilisation of marineWIND ENERGY Wind Energ. 2013; 16:77­90 Published online 19 March 2012 in Wiley Online Library

Papalambros, Panos

476

Accurate estimation of third-order moments from turbulence measurements  

E-Print Network [OSTI]

Politano and Pouquet's law, a generalization of Kolmogorov's four-fifths law to incompressible MHD, makes it possible to measure the energy cascade rate in incompressible MHD turbulence by means of third-order moments. In hydrodynamics, accurate measurement of third-order moments requires large amounts of data because the probability distributions of velocity-differences are nearly symmetric and the third-order moments are relatively small. Measurements of the energy cascade rate in solar wind turbulence have recently been performed for the first time, but without careful consideration of the accuracy or statistical uncertainty of the required third-order moments. This paper investigates the statistical convergence of third-order moments as a function of the sample size N. It is shown that the accuracy of the third-moment depends on the number of correlation lengths spanned by the data set and a method of estimating the statistical uncertainty of the third-moment is developed. The technique is illustrated usi...

Podesta, J J; Smith, C W; Elton, D C; Malecot, Y; Gagne, Y

2009-01-01T23:59:59.000Z

477

Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent  

E-Print Network [OSTI]

Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent Boundary Layers) of reacting hypersonic turbulent boundary layers at conditions typical of reen- try vehicles. Surface heat in designing hypersonic vehicles is to predict aerothermo- dynamic heating. When the boundary layer

Martín, Pino

478

Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers  

E-Print Network [OSTI]

Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers Lian Duan and M of the turbulence-chemistry interaction (TCI) are performed in hypersonic tur- bulent boundary layers using direct numerical simulation (DNS) flow fields under typical hypersonic conditions representative of blunt

Martín, Pino

479

Heat release effects on decaying homogeneous compressible turbulence  

E-Print Network [OSTI]

turbulence. A good understanding of high-enthalpy compressible turbulence is crucial for analyzing the flow around re-entry spacecrafts and hypersonic flight vehicles, and inside scramjet engines. One main factor affecting turbulence in these high...

Lee, Kurn Chul

2009-05-15T23:59:59.000Z

480

Wind Power Outreach Campaign  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption byAbout PrintableBlenderWhatFellows - PastFarmWindWind Power Wind

Note: This page contains sample records for the topic "temperature turbulence wind" 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.


481

Formation of Turbulent Cones in Accretion Disk Outflows and Application to Broad Line Regions of Active Galactic Nuclei  

E-Print Network [OSTI]

We consider the stability of an accretion disk wind to cloud formation when subject to a central radiation force. For a vertical launch velocity profile that is Keplerian or flatter and the presence of a significant radiation pressure, the wind flow streamlines cross in a conical layer. We argue that such regions are highly unstable, and are natural sites for supersonic turbulence and, consequently, density compressions. We suggest that combined with thermal instability these will all conspire to produce clouds. Such clouds can exist in dynamical equilibrium, constantly dissipating and reforming. As long as there is an inner truncation radius to the wind, our model emerges with a biconical structure similar to that inferred by Elvis (2000) for the broad line region (BLR) of active galactic nuclei (AGN). Our results may also apply to other disk-wind systems.

A. Y. Poludnenko; E. G. Blackman; A. Frank

2002-01-24T23:59:59.000Z

482

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

E-Print Network [OSTI]

Energy Efficiency and Renewable Energy, Wind and Hydropowerin Spain. Spanish Wind Energy Association (AEE) contributionin a Wind Turbine. Wind Energy (9:12); pp. 141161.

Lantz, Eric

2014-01-01T23:59:59.000Z

483

20% Wind Energy by 2030 - Chapter 6: Wind Power Markets Summary...  

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

6: Wind Power Markets Summary Slides 20% Wind Energy by 2030 - Chapter 6: Wind Power Markets Summary Slides Summary slides overviewing wind power markets, growth, applications, and...

484

Collegiate Wind Competition Turbines go Blade-to-Blade in Wind...  

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

This wind tunnel constructed by NREL engineers will test the small wind turbines designed by 10 university teams competing in DOE's Collegiate Wind Competition. This wind tunnel...

485

Poincare recurrence and spectral cascades in three-dimensional quantum turbulence  

SciTech Connect (OSTI)

The time evolution of the ground state wave function of a zero-temperature Bose-Einstein condensate (BEC) gas is well described by the Hamiltonian Gross-Pitaevskii (GP) equation. Using a set of appropriately interleaved unitary collision-stream operators, a qubit lattice gas algorithm is devised, which on taking moments, recovers the Gross-Pitaevskii (GP) equation under diffusion ordering (time scales as length{sup 2}). Unexpectedly, there is a class of initial states whose Poincare recurrence time is extremely short and which, as the grid resolution is increased, scales with diffusion ordering (and not as length{sup 3}). The spectral results of J. Yepez et al.[Phys. Rev. Lett. 103, 084501 (2009).] for quantum turbulence are revised and it is found that it is the compressible kinetic energy spectrum that exhibits three distinct spectral regions: a small-k classical-like Kolmogorov k{sup -5/3}, a steep semiclassical cascade region, and a large-k quantum vortex spectrum k{sup -3}. For most evolution times the incompressible kinetic energy spectrum exhibits a somewhat robust quantum vortex spectrum of k{sup -3} for an extended range in k with a k{sup -3.4} spectrum for intermediate k. For linear vortices of winding number 1 there is an intermittent loss of the quantum vortex cascade with its signature seen in the time evolution of the kinetic energy E{sub kin}(t), the loss of the quantum vortex k{sup -3} spectrum in the incompressible kinetic energy spectrum as well as the minimalization of the vortex core isosurfaces that would totally inhibit any Kelvin wave vortex cascade. In the time intervals around these intermittencies the incompressible kinetic energy also exhibits a multicascade spectrum.

Vahala, George; Zhang Bo [Department of Physics, William and Mary, Williamsburg, Virginia 23185 (United States); Yepez, Jeffrey [Air Force Research Laboratory, Hanscom Air Force Base, Massachusetts 01731 (United States); Vahala, Linda [Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States); Soe, Min [Department of Mathematics and Physical Sciences, Rogers State University, Claremore, Oklahoma 74017 (United States); Ziegeler, Sean [High Performance Technologies, Inc., Reston, Virginia 20190 (United States)

2011-10-15T23:59:59.000Z

486

Community Wind Benefits (Fact Sheet)  

SciTech Connect (OSTI)

This fact sheet explores the benefits of community wind projects, including citations to published research.

Not Available

2012-11-01T23:59:59.000Z

487

wind engineering & natural disaster mitigation  

E-Print Network [OSTI]

wind engineering & natural disaster mitigation #12;wind engineering & natural disaster mitigation Investment WindEEE Dome at Advanced Manufacturing Park $31million Insurance Research Lab for Better Homes $8million Advanced Facility for Avian Research $9million #12;wind engineering & natural disaster mitigation

Denham, Graham

488

Optimization of Wind Turbine Operation  

E-Print Network [OSTI]

Optimization of Wind Turbine Operation by Use of Spinner Anemometer TF Pedersen, NN Sørensen, L Title: Optimization of Wind Turbine Operation by Use of Spinner Anemometer Department: Wind Energy prototype wind turbine. Statistics of the yaw error showed an average of about 10°. The average flow

489

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network [OSTI]

some wind turbine manufacturers experienced blade andwind turbine manufacturers: Vestas (nacelles, blades, and

Bolinger, Mark

2010-01-01T23:59:59.000Z

490

Kentish Flats Offshore Wind Farm  

E-Print Network [OSTI]

Kentish Flats Offshore Wind Farm #12;By August 2005 the offshore wind farm at Kentish Flats plateau just outside the main Thames shipping lanes. The Kentish Flats wind farm will comprise 30 of the wind farm could be up to 90 MW. For the benefit of the environment The British Government has set

Firestone, Jeremy

491

Coupling a Mesoscale Numerical Weather Prediction Model with Large-Eddy Simulation for Realistic Wind Plant Aerodynamics Simulations (Poster)  

SciTech Connect (OSTI)

Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.

Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.

2014-06-01T23:59:59.000Z

492

Wind Power in Alaska  

Broader source: Energy.gov [DOE]

In the past few years wind power has become more and more prevalent across Alaska, with big turbines sprouting up in all parts of the state. Sponsored by the Renewable Energy Alaska Project, event...

493

DOE Collegiate Wind Competition  

Broader source: Energy.gov [DOE]

The U.S. Department of Energy (DOE) Collegiate Wind Competition will take place concurrently with the 2014 AWEA WINDPOWER Conference and Exhibition in Las Vegas. Spectators are encouraged to attend...

494

Airborne Wind Turbine  

SciTech Connect (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

495

Wind Turbines Benefit Crops  

ScienceCinema (OSTI)

Ames Laboratory associate scientist Gene Takle talks about research into the effect of wind turbines on nearby crops. Preliminary results show the turbines may have a positive effect by cooling and drying the crops and assisting with carbon dioxide uptake.

Takle, Gene

2013-03-01T23:59:59.000Z

496

Wind Agreements (Nebraska)  

Broader source: Energy.gov [DOE]

These regulations address leases or lease options securing land for the study or production of wind-generated energy. The regulations describe agreement terms, compliance, and a prohibition on land...

497

Model Wind Ordinance  

Broader source: Energy.gov [DOE]

''Note: This model ordinance was designed to provide guidance to local governments that wish to develop their own siting rules for wind turbines. While it was developed as part of a cooperative...

498

Solar and Wind Rights  

Broader source: Energy.gov [DOE]

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...

499

Wind Energy Systems Exemption  

Broader source: Energy.gov [DOE]

Tennessee House Bill 809, enacted into law in Public Chapter 377, Acts of 2003 and codified under Title 67, Chapter 5, states that wind energy systems operated by public utilities, businesses or...

500

Wind Energy Permitting Standards  

Broader source: Energy.gov [DOE]

All wind facilities larger than 0.5 megawatts (MW) that begin construction after July 1, 2010, must obtain a permit from any county in which the facility is located. Facilities must also obtain...