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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

An anisotropic-Alfvenic-turbulence-based solar wind model with proton temperature anisotropy  

E-Print Network [OSTI]

How the solar wind is accelerated to its supersonic speed is intimately related to how it is heated. Mechanisms based on ion-cyclotron resonance have been successful in explaining a large number of observations, those concerning the significant ion temperature anisotropy above coronal holes in particular. However, they suffer from the inconsistency with turbulence theory which says that the turbulent cascade in a low-beta medium like the solar corona should proceed in the perpendicular rather than the parallel direction, meaning that there is little energy in the ion gyro-frequency range for ions to absorb via ion-cyclotron resonance. Recently a mechanism based on the interaction between the solar wind particles and the anisotropic turbulence has been proposed, where the perpendicular proton energy addition is via the stochastic heating (Chandran et al. 2011). We extend this promising mechanism by properly accounting for the effect of proton temperature anisotropy on the propagation of Alfven waves, for the r...

Li, Bo

2012-01-01T23:59:59.000Z

2

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...

3

Supercomputers Capture Turbulence in the Solar Wind  

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

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

4

Supercomputers Capture Turbulence in the Solar Wind  

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

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

5

Can Wind Lidars Measure Turbulence?  

Science Journals Connector (OSTI)

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

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

2011-07-01T23:59:59.000Z

6

The Influence of Turbulence and Vertical Wind Profile in Wind Turbine Power Curve  

Science Journals Connector (OSTI)

To identify the influence of turbulence and vertical wind profile in wind turbine performance, wind speed measurements at different heights have been ... equipment, specifically a pulsed wave one. The wind profil...

A. Honrubia; A. Vigueras-Rodríguez…

2012-01-01T23:59:59.000Z

7

Nature of Subproton Scale Turbulence in the Solar Wind  

Science Journals Connector (OSTI)

The nature of subproton scale fluctuations in the solar wind is an open question, partly because two similar types of electromagnetic turbulence can occur: kinetic Alfvén turbulence and whistler turbulence. These two possibilities, however, have one key qualitative difference: whistler turbulence, unlike kinetic Alfvén turbulence, has negligible power in density fluctuations. In this Letter, we present new observational data, as well as analytical and numerical results, to investigate this difference. These results show, for the first time, that the fluctuations well below the proton scale are predominantly kinetic Alfvén turbulence, and, if present at all, the whistler fluctuations make up only a small fraction of the total energy.

C. H. K. Chen; S. Boldyrev; Q. Xia; J. C. Perez

2013-05-31T23:59:59.000Z

8

Coupled multi-body dynamics and CFD for wind turbine simulation including explicit wind turbulence  

Science Journals Connector (OSTI)

Abstract A high fidelity approach for wind turbine aero-elastic simulations including explicit representation of the atmospheric wind turbulence is presented. The approach uses a dynamic overset computational fluid dynamics (CFD) code for the aerodynamics coupled with a multi-body dynamics (MBD) code for the motion responses to the aerodynamic loads. Mann's wind turbulence model was implemented into the CFD code as boundary and initial conditions. The wind turbulence model was validated by comparing the theoretical one-point spectrum for the three components of the velocity fluctuations, and by comparing the expected statistics from the CFD simulated wind turbulent field with the explicit wind turbulence inlet boundary from Mann model. Extensive simulations based on the proposed coupled approach were conducted with the conceptual NREL 5-MW offshore wind turbine in an increasing level of complexity, analyzing the turbine behavior as elasticity, wind shear and atmospheric wind turbulence are added to the simulations. Results are compared with the publicly available simulations results from OC3 participants, showing good agreement for the aerodynamic loads and blade tip deflections in time and frequency domains. Wind turbulence/turbine interaction was examined for the wake flow. It was found that explicit turbulence addition results in considerably increased wake diffusion. The coupled CFD/MBD approach can be extended to include multibody models of the shaft, bearings, gearbox and generator, resulting in a promising tool for wind turbine design under complex operational environments.

Y. Li; A.M. Castro; T. Sinokrot; W. Prescott; P.M. Carrica

2015-01-01T23:59:59.000Z

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

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

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

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

13

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

14

Turbulence Characteristics in Offshore Wind Farms from LES Simulations of Lillgrund Wind Farm  

Science Journals Connector (OSTI)

Abstract The effect of wind turbine wakes in large offshore wind energy arrays can be a substantial factor in affecting the performance of turbines inside the array. Turbulent mixing plays a key role in the wake recovery, having a significant effect on the length over which the wake is strong enough to affect the performance of other turbines significantly. We highlight how turbulence affects wind turbine wakes using results from LES simulations of Lillgrund offshore wind farm in the context of SCADA data selected to mirror the wind conditions simulated. The analysis here concentrated on temporal spectra of wind velocities measured by the turbine's nacelle anemometer and calculated at the turbine locations in the computational model. The effect of the wind turbine rotor on the downstream flow is quantified by analysing the change in spectral features of turbines within the wind farm compared to turbines at the side of the farm exposed to the wind.

Wolf-Gerrit Früh; Angus C.W. Creech; A. Eoghan Maguire

2014-01-01T23:59:59.000Z

15

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

E-Print Network [OSTI]

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

Rudakov, L; Ganguli, G; Mithaiwala, M

2010-01-01T23:59:59.000Z

16

Wind noise and the spectrum of atmospheric turbulence pressure fluctuations  

Science Journals Connector (OSTI)

Previous research [S. Morgan and R. Raspet J. Acoust. Soc. Am. 92 1180–1183 (1992)] has shown that wind noise is predominantly caused by pressure fluctuations intrinsic to the turbulent atmospheric flow. Therefore it should be possible to predict wind noise from models for turbulent pressure spectra in the atmosphere. Based on simple dimensional analysis and an application of Taylor’s hypothesis the inertial?subrange power spectrum for turbulent pressure fluctuations should be proportional to f ?7/3 where f is frequency. But more recent atmospheric observations and theoretical arguments [J. D. Albertson G. G. Katul M. B. Parlange and W. E. Eichinger Phys. Fluids 10 1725–1732 (1998)] suggest that the power spectrum actually goes as f ?3/2. In this paper it is shown that the f ?3/2 dependence predicts a much slower decay in wind noise with increasing acoustic frequency than is typically observed. Possible reasons for this discrepancy are discussed.

2003-01-01T23:59:59.000Z

17

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

18

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

19

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

20

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.

Vörös, Z; Semenov, V S; Zaqarashvili, T V; Bruno, R; Khodachenko, 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.


21

Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loadings  

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.

2012-01-01T23:59:59.000Z

22

Two-Dimensional Kinetic Turbulence in the Solar Wind  

Science Journals Connector (OSTI)

We present the first 2D hybrid-Vlasov simulations of turbulence in the solar wind that describe the evolution of the energy spectra in a range of two decades of wavelengths around the ion inertial scale. Several previous magnetohydrodynamics and particle-in-cell simulations in the range of large (fluid) wavelengths showed a marked anisotropy of the energy spectra in the direction perpendicular to the mean magnetic field. Here we give evidence that the parallel direction can also be a privileged way for turbulence to develop towards short scales, where kinetic effects govern the plasma dynamics.

F. Valentini; F. Califano; P. Veltri

2010-05-17T23:59:59.000Z

23

Long-distance seed dispersal by wind: disentangling the effects of species traits, vegetation types, vertical turbulence and wind speed  

Science Journals Connector (OSTI)

Long-distance dispersal (LDD) of plant seeds by wind is affected by functional traits of the ... , as well as by the meteorological parameters wind speed and vertical turbulence. The relative importance of ... fo...

Felix Heydel; Sarah Cunze; Markus Bernhardt-Römermann…

2014-07-01T23:59:59.000Z

24

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

25

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

E-Print Network [OSTI]

of POD modes needed to accurately describe wind turbine blade and tower loads depends primarilyOn 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

Manuel, Lance

26

An internal winding high temperature heater  

Science Journals Connector (OSTI)

An internal winding high temperature heater ... General principles are outlined for the construction of compact heaters that are suitable for heating small containers or reaction vessels at constant temperature and up to about 1000 C. ...

A. J. Delbouille; E. G. Derouane

1973-01-01T23:59:59.000Z

27

The translation of turbulent wind energy to individual corn plant motion during senescense  

Science Journals Connector (OSTI)

Wind flow within inflexible plant canopies is turbulent and leads to an oscillatory motion of individual plants. A study was conducted to describe the motion of corn (Zea mays...L.) stalks in the wind using a tra...

T. K. Flesch; R. H. Grant

1991-04-01T23:59:59.000Z

28

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

29

Turbulent Temperature Fluctuations in the Princeton Large Tokamak Plasma  

Science Journals Connector (OSTI)

We present the first experimental evidence for the existence of turbulent temperature fluctuations in plasmas. These measurements were accomplished by a spectral analysis of blackbody electron cyclotron emission. The fractional fluctuation in the mean electron energy is up to 10% for typical Princeton Large Tokamak discharges. The spectrum of temperature turbulence extends well beyond the electron diamagnetic-drift frequency f* and shows no resemblance to the simultaneously existing turbulent density fluctuations.

V. Arunasalam; R. Cano; J. C. Hosea; E. Mazzucato

1977-10-03T23:59:59.000Z

30

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

31

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 for a utility-scale 5MW wind turbine. Load statistics, spectra, and time-frequency analysis representations utility-scale wind turbines. The present study takes on this question by making use of conventional

Manuel, Lance

32

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

33

Large-Eddy Simulation of Langmuir Turbulence in Pure Wind Seas  

Science Journals Connector (OSTI)

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

Ramsey R. Harcourt; Eric A. D’Asaro

2008-07-01T23:59:59.000Z

34

Simulation of Turbulent Flow Inside and Above Wind Farms: Model Validation and Layout Effects  

Science Journals Connector (OSTI)

A recently-developed large-eddy simulation framework is validated and used to investigate turbulent flow within and above wind farms under neutral conditions. Two different layouts are considered, consisting of t...

Yu-Ting Wu; Fernando Porté-Agel

2013-02-01T23:59:59.000Z

35

Large Eddy Simulation of Wind Turbulence for Appropriate Urban Environment  

Science Journals Connector (OSTI)

This study shows the numerical model which has the actual shape of the urban surface in order to analyze the wind turbulence in a city by large eddy simulation (LES) technique. Predictive accuracy of LES ... haza...

Tetsuro Tamura

2010-01-01T23:59:59.000Z

36

Turbulence Patch Identification in Potential Density or Temperature Profiles  

Science Journals Connector (OSTI)

The Thorpe analysis is a recognized method used to identify and characterize turbulent regions within stably stratified fluids. By comparing an observed profile of potential temperature or potential density to a reference profile obtained by ...

Richard Wilson; Hubert Luce; Francis Dalaudier; Jacques Lefrère

2010-06-01T23:59:59.000Z

37

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; published 16 September 2009. [1] Previous formulations of heating and transport associated with strong and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both

Oughton, Sean

38

Alfven Wave Turbulence and Perpendicular Ion Temperatures in Coronal Holes  

E-Print Network [OSTI]

Low-frequency Alfven-wave turbulence causes ion trajectories to become chaotic, or "stochastic," when the turbulence amplitude is sufficiently large. Stochastic orbits enable ions to absorb energy from the turbulence, increasing the perpendicular ion temperature even when the fluctuation frequencies are too small for a cyclotron resonance to occur. In this paper, an analytic expression for the stochastic heating rate is used in conjunction with an observationally constrained turbulence model to obtain an analytic formula for the perpendicular ion temperature as a function of heliocentric distance r, ion mass, and ion charge in coronal holes for values of r between 2 and 15 solar radii (Rs). The resulting temperature profiles provide a good fit to observations of protons and OVI ions at 2Rs heating also offers a natural explanation for several detailed features of the UVCS observations, including the preferential and anisotropic h...

Chandran, Benjamin D G

2010-01-01T23:59:59.000Z

39

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

E-Print Network [OSTI]

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

Howes, G G

2011-01-01T23:59:59.000Z

40

Experimental evidence of phase coherence of magnetohydrodynamic turbulence in the solar wind: GEOTAIL satellite data  

Science Journals Connector (OSTI)

...research, the amplitude (power spectrum) has been discussed...Saito 1969) and the power-law type spectrum of...turbulence in the solar wind (Goldstein Roberts 1999...spacecraft in the solar wind. From the original data...original data into the power spectrum and the phases...

2008-01-01T23:59:59.000Z

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

Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)  

Science Journals Connector (OSTI)

...can, potentially, transfer mechanical energy to the stamens because of the predominant...spectrum of the wind turbulent kinetic energy. Also included are PSDs of (c) the displacement...28 Flesch, TK , and RH Grant. 1992 Corn motion in the wind during senescence...

2014-01-01T23:59:59.000Z

42

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

Science Journals Connector (OSTI)

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

Eric Danioux; Patrice Klein; Pascal Rivière

2008-10-01T23:59:59.000Z

43

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

44

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

E-Print Network [OSTI]

Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind; received in revised form 6 April 2005; accepted 25 April 2005 Abstract We present the solar wind plasma parameters obtained from the Wind spacecraft during more than nine years, encompassing almost the whole solar

California at Berkeley, University of

45

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.

46

Petascale Simulations of Inhomogeneous Alfven Turbulence in the Solar Wind  

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

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

47

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

48

REDUCTION OF DRIFT EFFECTS DUE TO SOLAR WIND TURBULENCE  

SciTech Connect (OSTI)

Gradient and curvature drift play a key role in the modulation of cosmic rays. Reduction in the drift coefficient due to turbulence has been demonstrated unambiguously through direct numerical simulations, but a theory that can explain these results is still lacking. We introduce a parameterized form of the drift coefficient based on direct numerical simulations and show that good agreement with observed proton energy spectra at Earth can be found when it is used in a numerical modulation model. We show that the turbulence ultrascale, for which no observations currently exist, plays an important role in drift reduction. The magnitude at Earth and spatial dependence of this quantity required to fit cosmic-ray observations at Earth are argued to be plausible based on the required properties of the two-dimensional turbulence spectrum at large scales.

Burger, R. A.; Visser, D. J. [Unit for Space Physics, North-West University, 2520 Potchefstroom (South Africa)

2010-12-10T23:59:59.000Z

49

A Model of Turbulence in Magnetized Plasmas: Implications for the Dissipation Range in the Solar Wind  

E-Print Network [OSTI]

This paper studies the turbulent cascade of magnetic energy in weakly collisional magnetized plasmas. A cascade model is presented, based on the assumptions of local nonlinear energy transfer in wavenumber space, critical balance between linear propagation and nonlinear interaction times, and the applicability of linear dissipation rates for the nonlinearly turbulent plasma. The model follows the nonlinear cascade of energy from the driving scale in the MHD regime, through the transition at the ion Larmor radius into the kinetic Alfven wave regime, in which the turbulence is dissipated by kinetic processes. The turbulent fluctuations remain at frequencies below the ion cyclotron frequency due to the strong anisotropy of the turbulent fluctuations, k_parallel cyclotron damping. The conditions under which the gyrokinetic cascade reaches the ion cyclotron frequency are established. Cascade model solutions imply that collisionless damping provides a natural explanation for the observed range of spectral indices in the dissipation range of the solar wind. The dissipation range spectrum is predicted to be an exponential fall off; the power-law behavior apparent in observations may be an artifact of limited instrumental sensitivity. The cascade model is motivated by a programme of gyrokinetic simulations of turbulence and particle heating in the solar wind.

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

2007-07-20T23:59:59.000Z

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

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

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

Turbulence effects on the wake flow and power production of a horizontal-axis wind turbine  

Science Journals Connector (OSTI)

Abstract This study experimentally investigated the effects of ambient turbulence on the wake flows and power production of a horizontal-axis wind turbine. The approaching flows included low-turbulence smooth flow and grid-generated turbulent flow. The profiles of time-averaged velocity, turbulence intensity and Reynolds stress from the intermediate to the far-wake regions were measured and compared for smooth and turbulent flows. Based on the measured data, prediction models for the centerline velocity deficit, turbulence intensity, wake radius and velocity profile were proposed. In addition, the experimental results showed that the power productions in the grid-generated turbulent flows were slightly higher than that in the smooth flow. But the power loss due to the velocity deficit in the wake flow was larger than 50% when the downwind distance was less than 12D (D is the rotor diameter). An empirical relation between the power production and the downwind distance x and lateral distance y was proposed.

Chia-Ren Chu; Pei-Hung Chiang

2014-01-01T23:59:59.000Z

54

SELF-CONSISTENT MODEL OF THE INTERSTELLAR PICKUP PROTONS, ALFVENIC TURBULENCE, AND CORE SOLAR WIND IN THE OUTER HELIOSPHERE  

SciTech Connect (OSTI)

A self-consistent model of the interstellar pickup protons, the slab component of the Alfvenic turbulence, and core solar wind (SW) protons is presented for r {>=} 1 along with the initial results of and comparison with the Voyager 2 (V2) observations. Two kinetic equations are used for the pickup proton distribution and Alfvenic power spectral density, and a third equation governs SW temperature including source due to the Alfven wave energy dissipation. A fraction of the pickup proton free energy, f{sub D} , which is actually released in the waveform during isotropization, is taken from the quasi-linear consideration without preexisting turbulence, whereas we use observations to specify the strength of the large-scale driving, C{sub sh}, for turbulence. The main conclusions of our study can be summarized as follows. (1) For C{sub sh} Almost-Equal-To 1-1.5 and f{sub D} Almost-Equal-To 0.7-1, the model slab component agrees well with the V2 observations of the total transverse magnetic fluctuations starting from {approx}8 AU. This indicates that the slab component at low-latitudes makes up a majority of the transverse magnetic fluctuations beyond 8-10 AU. (2) The model core SW temperature agrees well with the V2 observations for r {approx}> 20 AU if f{sub D} Almost-Equal-To 0.7-1. (3) A combined effect of the Wentzel-Kramers-Brillouin attenuation, large-scale driving, and pickup proton generated waves results in the energy sink in the region r {approx}< 10 AU, while wave energy is pumped in the turbulence beyond 10 AU. Without energy pumping, the nonlinear energy cascade is suppressed for r {approx}< 10 AU, supplying only a small energy fraction into the k-region of dissipation by the core SW protons. A similar situation takes place for the two-dimensional turbulence. (4) The energy source due to the resonant Alfven wave damping by the core SW protons is small at heliocentric distances r {approx}< 10 AU for both the slab and the two-dimensional turbulent components. As a result, adiabatic cooling mostly controls the model SW temperature in this region, and the model temperature disagrees with the V2 observations in the region r {approx}< 20 AU.

Gamayunov, Konstantin V.; Zhang Ming; Rassoul, Hamid K. [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Pogorelov, Nikolai V.; Heerikhuisen, Jacob, E-mail: kgamayunov@fit.edu [Department of Physics and Center for Space Physics and Aeronomic Research, University of Alabama, Huntsville, AL 35899 (United States)

2012-09-20T23:59:59.000Z

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); Gürcan, Ö. 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

New models for wind noise measured in a flat surface under turbulent flow.  

Science Journals Connector (OSTI)

We have previously developed models for predicting the power spectral density of the wind noisepressuremeasured in a flat plate outdoors from the measured power spectral density of the turbulence and the measured wind velocity profile above the plate [Yu et al. Proceedings of NCAD 2008 NoiseCon2008?ASME NCAD]. Recently we have corrected an error in the model for the logarithmic profile wind velocity gradient results and have developed an improved integration method. Also we have developed a prediction for arbitrary wind velocity profiles using the previous single exponential model. Typical results comparing our predictions with our measurements are presented and analyzed. A simple algebraic fit to the prediction for the logarithmic profile fit form is also provided for use by others. [Research supported by the U.S. Army TACOM?ARDEC at Picatinny Arsenal NJ.

2009-01-01T23:59:59.000Z

58

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

E-Print Network [OSTI]

and Panofsky (oa. cit. ) derived a CAT Index (I) which is proportional to the energy of the vertical component of turbulence. This expression is given by 2 I = (AV) (I - Ri/Ri . ) where QV is the magnitude of the vector difference in wind velocity over a... and energy to be felt as CAT could be generated. They analyzed 17 FPS-16 radar/Jimsphere wind profiles under conditions of weak anticyclonic flow. From their analysis, they estimated a functional relationship between Ri and the thickness, L, of the layer...

Blackburn, James Harvey

2012-06-07T23:59:59.000Z

59

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

Science Journals Connector (OSTI)

The intermittency in turbulent magnetic field fluctuations has been observed to scale with the amount of magnetic helicity injected into a laboratory plasma. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays turbulent magnetic and plasma fluctuations as it relaxes into a Taylor state. The level of intermittency of this turbulence is determined by finding the flatness of the probability distribution function of increments for magnetic pickup coil fluctuations B?(t). The intermittency increases with the injected helicity, but spectral indices are unaffected by this variation. While evidence is provided which supports the hypothesis that current sheets and reconnection sites are related to the generation of this intermittent signal, the true nature of the observed intermittency remains unknown.

D.?A. Schaffner; A. Wan; M.?R. Brown

2014-04-25T23:59:59.000Z

60

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

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61

The Role of Turbulence in Coronal Heating and Solar Wind Expansion  

E-Print Network [OSTI]

Plasma in the Sun's hot corona expands into the heliosphere as a supersonic and highly magnetized solar wind. This paper provides an overview of our current understanding of how the corona is heated and how the solar wind is accelerated. Recent models of magnetohydrodynamic turbulence have progressed to the point of successfully predicting many observed properties of this complex, multi-scale system. However, it is not clear whether the heating in open-field regions comes mainly from the dissipation of turbulent fluctuations that are launched from the solar surface, or whether the chaotic "magnetic carpet" in the low corona energizes the system via magnetic reconnection. To help pin down the physics, we also review some key observational results from ultraviolet spectroscopy of the collisionless outer corona.

Cranmer, S R; Miralles, M P; Raymond, J C; Strachan, L; Tian, H; Woolsey, L N

2014-01-01T23:59:59.000Z

62

Magnetohydrodynamic simulation of the radial evolution and stream structure of solar-wind turbulence  

Science Journals Connector (OSTI)

We present a unified interpretation of observations of interplanetary fluctuations in terms of nearly incompressible magnetohyrodynamics. Incompressive effects explain the rapid evolution of turbulence in slow wind containing the heliospheric current sheet. The relative constancy of the spectrum of ‘‘inward propagating’’ fluctuations compared to the rapid decline in ‘‘outward’’ fluctuations results from incompressive spectral transfer combined with strong dissipation of the outward fluctuations. Secondary compressive effects account for nearly pressure-balanced structures and the density fluctuation levels.

D. Aaron Roberts; Sanjoy Ghosh; Melvyn L. Goldstein; William H. Mattheaus

1991-12-30T23:59:59.000Z

63

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

64

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

65

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

66

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

SciTech Connect (OSTI)

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

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

67

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...

68

The PNL single-tower measurement model of rotationally sampled turbulent wind, with user's guide for STRS2PC  

SciTech Connect (OSTI)

This report describes a single-tower rotationally sampled wind model, STRS-2, that approximates a set of time series of turbulent wind experienced by individual points rotating in circles in a crosswind plane using measurements from anemometers arrayed vertically along a single line. The purposes of the model are (1) to use turbulence measurements made economically from conventional single-tower arrays of anemometers, (2) to incorporate measures characteristics of the wind at specific sites under consideration for operation of wind turbines, spanning the height range if interest, and (3) to estimate the unmeasured turbulence characteristics in the crosswind plane that spans the disk of the rotor blades. 17 refs., 15 figs., 5 tabs.

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

1988-06-01T23:59:59.000Z

69

Kinetic cascade beyond MHD of solar wind turbulence in two-dimensional hybrid simulations  

E-Print Network [OSTI]

The nature of solar wind turbulence in the dissipation range at scales much smaller than the large MHD scales remains under debate. Here a two-dimensional model based on the hybrid code abbreviated as A.I.K.E.F. is presented, which treats massive ions as particles obeying the kinetic Vlasov equation and massless electrons as a neutralizing fluid. Up to a certain wavenumber in the MHD regime, the numerical system is initialized by assuming a superposition of isotropic Alfv\\'en waves with amplitudes that follow the empirically confirmed spectral law of Kolmogorov. Then turbulence develops and energy cascades into the dispersive spectral range, where also dissipative effects occur. Under typical solar wind conditions, weak turbulence develops as a superposition of normal modes in the kinetic regime. Spectral analysis in the direction parallel to the background magnetic field reveals a cascade of left-handed Alfv\\'en/ion-cyclotron waves up to wave vectors where their resonant absorption sets in, as well as a cont...

Verscharen, Daniel; Motschmann, Uwe; Müller, Joachim

2012-01-01T23:59:59.000Z

70

Validating a Time-Dependent Wave-Turbulence-Driven Model of the Solar Wind  

E-Print Network [OSTI]

Although the mechanisms responsible for heating the Sun's corona and accelerating the solar wind are still being actively investigated, it is largely accepted that photospheric motions provide the energy source and that the magnetic field must play a key role in the process. \\citet{2010ApJ...708L.116V} presented a model for heating and accelerating the solar wind based on the turbulent dissipation of Alfv\\'en waves. We first use a time-dependent model of the solar wind to reproduce one of \\citeauthor{2010ApJ...708L.116V}'s solutions; then we extend its application to the case when the energy equation includes thermal conduction and radiation losses, and the upper chromosphere is part of the computational domain. Using this model, we explore parameter space and describe the characteristics of a fast-solar-wind solution. We discuss how this formulation may be applied to a 3D MHD model of the coron a and solar wind \\citep{2009ApJ...690..902L}.

Lionello, Roberto; Downs, Cooper; Linker, Jon A; Miki?, Zoran; Verdini, Andrea

2014-01-01T23:59:59.000Z

71

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

E-Print Network [OSTI]

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

A. Bershadskii

2009-08-27T23:59:59.000Z

72

Characterization of the SUMO Turbulence Measurement System for Wind Turbine Wake Assessment  

Science Journals Connector (OSTI)

Abstract The remotely piloted aircraft system (RPAS) SUMO (Small Unmanned Meteorological Observer) has been equipped with a miniaturized 5-hole probe sensor system for measurement of the 3-dimensional flow vector with a temporal resolution of 100 Hz. Due to its’ weight and size this system is particularly well suited for operations in the vicinity of wind turbines. To qualify for full scale measurements in turbine wakes the system has been characterized by several laboratory and field tests described in this study. A wind tunnel test against a hot-wire anemometer shows the capability of the 5-hole probe to react to turbulence in the same manner as the hot-wire system. The resulting spectra from the two platforms show in general good agreement for both laminar and turbulent flows. The 5-hole probe system is able to resolve turbulence up to frequencies around 20 ? 30 Hz when using a tubing length of 15 cm between the probe and the pressure transducers. In addition, an environmental parallel test against to two sonic anemometers mounted on the roof-top of a car was performed at Bergen airport Flesland. Despite several issues with the self-made and low-cost experimental setup, important system characteristics could be tested and verified. In particular the velocity spectral components of the sonic anemometer system and the 5-hole probe are in close resemblance to each other. This is at least a strong indication that the 5-hole probe is suitable for atmospheric turbulence measurements onboard the RPAS SUMO platform.

Line Båserud; Martin Flügge; Anak Bhandari; Joachim Reuder

2014-01-01T23:59:59.000Z

73

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

74

Comparing Wind, Temperature, Pressure, and Humidity  

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

the higher the amount of energy in the air. Temperature is measured using a thermometer with units in degrees Celsius or Fahrenheit. See http:www.teachervision.com...

75

Kinetic cascade beyond magnetohydrodynamics of solar wind turbulence in two-dimensional hybrid simulations  

Science Journals Connector (OSTI)

The nature of solar windturbulence in the dissipation range at scales much smaller than the large magnetohydrodynamic (MHD) scales remains under debate. Here a two-dimensional model based on the hybrid code abbreviated as A.I.K.E.F. is presented which treats massive ions as particles obeying the kinetic Vlasov equation and massless electrons as a neutralizing fluid. Up to a certain wavenumber in the MHD regime the numerical system is initialized by assuming a superposition of isotropic Alfvén waves with amplitudes that follow the empirically confirmed spectral law of Kolmogorov. Then turbulence develops and energy cascades into the dispersive spectral range where also dissipative effects occur. Under typical solar wind conditions weak turbulence develops as a superposition of normal modes in the kinetic regime. Spectral analysis in the direction parallel to the background magnetic field reveals a cascade of left-handed Alfvén/ion-cyclotron waves up to wave vectors where their resonant absorption sets in as well as a continuing cascade of right-handed fast-mode and whistler waves. Perpendicular to the background field a broad turbulent spectrum is found to be built up of fluctuations having a strong compressive component. Ion-Bernstein waves seem to be possible normal modes in this propagation direction for lower driving amplitudes. Also signatures of short-scale pressure-balanced structures (very oblique slow-mode waves) are found.

D. Verscharen; E. Marsch; U. Motschmann; J. Müller

2012-01-01T23:59:59.000Z

76

The Role of Alpha Particles in the Evolution of the Solar-wind Turbulence toward Short Spatial Scales  

Science Journals Connector (OSTI)

We present a numerical study of the kinetic dynamics of protons and alpha particles during the evolution of the solar-wind turbulent cascade, in which the energy injected in large-scale slab-type Alfvénic fluctuations is transferred toward short spatial scale lengths, across the proton skin depth. We make use of a hybrid Vlasov-Maxwell code that integrates numerically the Vlasov equation for both the ion species, while the electrons are considered as a fluid. The system evolution is investigated in terms of different values of the electron to proton and alpha particle to proton temperature ratios. The numerical results show that the previously studied kinetic dynamics of protons is not strongly affected by the presence of alpha particles, at least when they are present in low concentration. Our simulations not only provide a physical explanation for the generation of beams of accelerated particles along the direction of the ambient magnetic field for both protons and alpha particles, but also show that this mechanism is more efficient for protons than for alpha particles, in agreement with recent solar-wind data analyses.

D. Perrone; F. Valentini; P. Veltri

2011-01-01T23:59:59.000Z

77

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

78

turbulence | OpenEI  

Open Energy Info (EERE)

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

79

Heat Transfer at Low Temperatures between Tube Walls and Gases in Turbulent Flow  

Science Journals Connector (OSTI)

...September 1947 research-article Heat Transfer at Low Temperatures between Tube...counter-flow system to study heat transfer between tube walls and gases at...Determinations on friction accompanying heat transfer with gases in turbulent flow at...

1947-01-01T23:59:59.000Z

80

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

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

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

82

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

83

A wind-tunnel investigation of the wind speed and turbulence characteristics close to the ground over various escarpment shapes  

Science Journals Connector (OSTI)

A wind-tunnel investigation of the wind flow over two-dimensional forward-facing escarpments ... into the effects of local topography on the wind flow close to the ground. Four sharp ... -wire anemometer. The mod...

A. J. Bowen; D. Lindley

1977-10-01T23:59:59.000Z

84

POSSIBLE EVIDENCE OF ALFVEN-CYCLOTRON WAVES IN THE ANGLE DISTRIBUTION OF MAGNETIC HELICITY OF SOLAR WIND TURBULENCE  

SciTech Connect (OSTI)

The fluctuating magnetic helicity is considered an important parameter in diagnosing the characteristic modes of solar wind turbulence. Among them is the Alfven-cyclotron wave, which is probably responsible for the solar wind plasma heating, but has not yet been identified from the magnetic helicity of solar wind turbulence. Here, we present the possible signatures of Alfven-cyclotron waves in the distribution of magnetic helicity as a function of {theta}{sub VB}, which is the angle between the solar wind velocity and local mean magnetic field. We use magnetic field data from the STEREO spacecraft to calculate the {theta}{sub VB} distribution of the normalized reduced fluctuating magnetic helicity {sigma}{sub m}. We find a dominant negative {sigma}{sub m} for 1 s < p < 4 s (p is time period) and for {theta}{sub VB} < 30 deg. in the solar wind outward magnetic sector, and a dominant positive {sigma}{sub m} for 0.4 s < p < 4 s and for {theta}{sub VB}>150 deg. in the solar wind inward magnetic sector. These features of {sigma}{sub m} appearing around the Doppler-shifted ion-cyclotron frequencies may be consistent with the existence of Alfven-cyclotron waves among the outward propagating fluctuations. Moreover, right-handed polarized waves at larger propagation angles, which might be kinetic Alfven waves or whistler waves, have also been identified on the basis of the {sigma}{sub m} features in the angular range 40 deg. < {theta}{sub VB} < 140 deg. Our findings suggest that Alfven-cyclotron waves (together with other wave modes) play a prominent role in turbulence cascading and plasma heating of the solar wind.

He Jiansen; Tu Chuanyi; Yao Shuo; Tian Hui [Department of Geophysics, Peking University, Beijing 100871 (China); Marsch, Eckart, E-mail: jshept@gmail.com [Max-Planck-Institut fuer Sonnensystemforschung, 37191 Katlenburg-Lindau (Germany)

2011-04-20T23:59:59.000Z

85

Statistics and scaling properties of temperature field in symmetrical non-Oberbeck-Boussinesq turbulent convection  

E-Print Network [OSTI]

The influence of symmetrical non-Oberbeck-Boussinesq (SNOB) effect on statistical and scaling properties of temperature field in turbulent convection is investigated experimentally in $SF_{6}$ in the vicinity of its gas-liquid critical point (CP). The main conclusion of the studies is that besides the strong $Ra$ and $Pr$ dependence of the rms of temperature fluctuations normalized by the temperature difference across the cell, different from the Oberbeck-Boussinesq (OB) case of turbulent convection, all rest of statistical and scaling properties of temperature field discussed in details are the same as in the OB case.

Yuri Burnishev; Victor Steinberg

2011-08-31T23:59:59.000Z

86

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

SciTech Connect (OSTI)

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

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

2012-08-01T23:59:59.000Z

87

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

88

VOL. 19 NO. 1 ACTA METEOROLOGICA SINICA 2005 Numerical Simulation of Wind and Temperature Fields  

E-Print Network [OSTI]

VOL. 19 NO. 1 ACTA METEOROLOGICA SINICA 2005 Numerical Simulation of Wind and Temperature Fields of fuel consumed in the Xi'an industrial area. Tong and Sang (2002) simulated the wind, temperature that the wind field is affected by the topography and urban heat island. Yang et al. (2003) simulated the winter

Thompson, Anne

89

Nonlinear Gyrokinetic Simulations of Ion-Temperature-Gradient Turbulence for the Optimized Wendelstein 7-X Stellarator  

SciTech Connect (OSTI)

Ion-temperature-gradient turbulence constitutes a possibly dominant transport mechanism for optimized stellarators, in view of the effective suppression of neoclassical losses characterizing these devices. Nonlinear gyrokinetic simulation results for the Wendelstein 7-X stellarator [G. Grieger et al., in Proceedings of the IAEA Conference on Plasma Physics and Controlled Nuclear Fusion Research, 1990 (IAEA, Vienna, 1991) Vol. 3, p. 525]--assuming an adiabatic electron response--are presented. Several fundamental features are discussed, including the role of zonal flows for turbulence saturation, the resulting flux-gradient relationship, and the coexistence of ion-temperature-gradient modes with trapped ion modes in the saturated state.

Xanthopoulos, P. [Max-Planck-Institut fuer Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); Merz, F.; Goerler, T.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

2007-07-20T23:59:59.000Z

90

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

91

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

92

Temperature gradients, and search for non-Boussinesq effects, in the interior of turbulent Rayleigh-Bnard convection  

E-Print Network [OSTI]

Temperature gradients, and search for non-Boussinesq effects, in the interior of turbulent Rayleigh.1209/0295-5075/80/14001 Temperature gradients, and search for non-Boussinesq effects, in the interior of turbulent Rayleigh symmetry-breaking deviations from the Oberbeck-Boussinesq approximation even under conditions where

Haller, Gary L.

93

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

94

Impacts of wind farms on surface air temperatures  

Science Journals Connector (OSTI)

...AS Keith DW ( 2007 ) Wind energy and climate...atmospheric impacts of wind energy turbines . EOS Trans AGU 88 : Fall Meeting...Global potential for wind-generated electricity...JF McGowan JG ( 2005 ) Offshore wind farm layout optimization...

Somnath Baidya Roy; Justin J. Traiteur

2010-01-01T23:59:59.000Z

95

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

96

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.

97

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....

98

Turbulence  

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

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

99

Effects of high-frequency wind sampling on simulated mixed layer depth and upper ocean temperature  

E-Print Network [OSTI]

Effects of high-frequency wind sampling on simulated mixed layer depth and upper ocean temperature. Citation: Lee, T., and W. T. Liu (2005), Effects of high-frequency wind sampling on simulated mixed layer 2005. [1] Effects of high-frequency wind sampling on a near-global ocean model are studied by forcing

Talley, Lynne D.

100

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature  

E-Print Network [OSTI]

(WRF) and COAMPS atmospheric models. The SST-induced wind response is assessed from eight simulations of the surface wind relative to the SST gradient. #12;3 1. Introduction Positive correlations of local surfaceModeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Natalie

Kurapov, Alexander

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

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature  

E-Print Network [OSTI]

to local SST perturbations decreases rapidly with height to near-zero at 150-300m. The simulated wind speed of local SST perturbations, and the orientation of the surface wind to the SST gradient. #12;3 1. Introduction Positive correlations of local surface wind anomalies with sea surface temperature (SST) anomalies

102

Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)  

Science Journals Connector (OSTI)

...00, stamens were filmed and wind velocity was sampled over 9-min...the analysis. Fluctuations in wind velocity (u, v, w) were...energy for the fluctuations. Power spectral densities (PSDs...displacements and 12.5 Hz for wind velocities. The acceleration...

2014-01-01T23:59:59.000Z

103

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

104

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

105

The radial temperature profile of the solar wind John D. Richardson  

E-Print Network [OSTI]

The radial temperature profile of the solar wind John D. Richardson Center for Space Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA Charles W. Smith Bartol Research Institute but do not account for the smaller scale (few AU) temperature variations. At 1 AU, the solar wind

Richardson, John

106

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

107

Petascale Simulations of Inhomogeneous Alfvén Turbulence in the Solar Wind  

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

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

108

Considerations of ion-temperature-gradient-driven turbulence  

SciTech Connect (OSTI)

The ion-temperature-gradient-driven instability is considered in this paper. Physical pictures are presented to clarify the nature of the instability. The saturation of a single eddy is modeled by a simple nonlinear equation. It is shown that eddies that are elongated in the direction of the temperature gradient are the most unstable and have the highest saturation amplitudes. In a sheared magnetic field, such elongated eddies twist with the field lines. This structure is shown to be an alternative to the usual Fourier mode picture in which the mode is localized around the surface where {ital k}{sub {parallel}} =0. These elongated twisting eddies, which are an integral part of the ballooning mode'' structure, could survive in a torus. The elongated eddies are shown to be unstable to secondary instabilities that are driven by the large gradients in the long eddy. It is argued that the mixing length'' is affected by this nonlinear process, and is unlikely to be a linear eigenmode width.

Cowley, S.C.; Kulsrud, R.M. (Princeton Plasma Physics Laboratory, Princeton, New Jersey (USA)); Sudan, R. (Cornell University, Ithaca, New York (USA))

1991-10-01T23:59:59.000Z

109

Heat transfer and temperature distribution in a turbulent flow over a flat plate with an unheated starting length  

SciTech Connect (OSTI)

The present study is a numerical investigation of heat transfer and temperature distribution in a boundary layer formed by a flow with nonzero free stream turbulence over a flat plate with an unheated starting length. The numerical method is based on the Reynolds-averaged equations of motion and energy. As a closure for the Reynolds- averaged equations the Hinze relations for turbulent shear stresses and for turbulent heat flux are used. The Hinze equations are used instead of the usually employed Boussinesq eddy-viscosity hypothesis, because the latter does not work properly for flows with high free stream turbulence. It is shown in the present study that the influence of an unheated starting length on a temperature profile has manifested itself similarly to the influence of the free stream turbulence and resulted in a temperature profile with negative profile parameter. Unlike the flow with zero free stream turbulence, a heat transfer coefficient for the part of the plate with an unheated starting length can be less than for the fully heated plate. This difference increases with increasing level of the free stream turbulence. The family of functions that describe the influence of an unheated starting length for flows with nonzero free stream turbulence is presented.

Fridman, E.

1997-07-01T23:59:59.000Z

110

3D Turbulence Measurements Using Three Synchronous Wind Lidars: Validation against Sonic Anemometry  

Science Journals Connector (OSTI)

This paper presents a technique to measure the time series of the three components of the wind vector at a point in space from synchronous measurements of three scanning Doppler wind lidars. Knowing the position of each lidar on the ground and the ...

Fernando Carbajo Fuertes; Giacomo Valerio Iungo; Fernando Porté-Agel

2014-07-01T23:59:59.000Z

111

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

112

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

Science Journals Connector (OSTI)

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

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

2012-11-01T23:59:59.000Z

113

Universal power spectra for acoustic turbulence: Applications to wind waves, 1/f noise, and classical second sound  

Science Journals Connector (OSTI)

A continuum pumped full of waveenergy at an amplitude sufficiently large so that reversible nonlinearities dominate irreversible linear response becomes waveturbulent. In the limit of high nonlinearity acoustic turbulence and wind waveturbulence accumulate at 1/f and 1/f 5 power spectra respectively. A waveturbulent system can support new propagating energy modes analogous to second sound in superfluid He4. This hyperbolic (nondiffusive) transport could account for the anomalous diffusivity observed in plasma devices and for the difficulties faced in achieving confinement. The key to the understanding of these phenomena is the nonlinearity in the continuum mechanics which leads to three basic effects: (1) scattering of sound by sound to produce waves with sum and difference frequencies; (2) refraction of waves by a slowly varying (inhomogeneous) background; (3) reaction of the background due to changes in the distribution of sound waves. Details of these processes are presented in the framework of the Euler equations.

Seth Putterman; A. Larraza; P. H. Roberts

1986-01-01T23:59:59.000Z

114

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

115

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

Science Journals Connector (OSTI)

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

Cheryl Klipp

2007-12-01T23:59:59.000Z

116

A PV View of the Zonal Mean Distribution of Temperature and Wind in the Extratropical Troposphere  

Science Journals Connector (OSTI)

The dependence of the temperature and wind distribution of the zonal mean flow in the extratropical troposphere on the gradient of potential vorticity along isentropes is examined. The extratropics here refer to the region outside the Hadley ...

De-Zheng Sun; Richard S. Lindzen

1994-03-01T23:59:59.000Z

117

Development and Investigation of a Dipole Magnet with a High-Temperature Superconductor Winding  

Science Journals Connector (OSTI)

The structure of a dipole magnet with an iron yoke, where the winding is made of a Bi-2223 high-temperature superconductor, has been developed and the magnet has been built at the Institute of High-Energy Physics...

A. I. Ageev; I. V. Bogdanov; V. V. Zubko; S. S. Kozub; K. P. Myznikov…

2002-12-01T23:59:59.000Z

118

Narrowband sodium lidar for the measurements of mesopause region temperature and wind  

Science Journals Connector (OSTI)

We report here a narrowband high-spectral resolution sodium temperature/wind lidar recently developed at the University of Science and Technology of China (USTC) in Hefei, China...

Li, Tao; Fang, Xin; Liu, Wei; Gu, Sheng-Yang; Dou, Xiankang

2012-01-01T23:59:59.000Z

119

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

E-Print Network [OSTI]

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

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

2010-01-01T23:59:59.000Z

120

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

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

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

122

Simplified turbulent spiral boundary layer and thermal wind simulator for acid rain modeling  

SciTech Connect (OSTI)

To determine the possible future impact of acid rain on the ecosystem requires the ability to numerically simulate the transport of various acids and their precursors from various sources to the locations of interest. Such a simulation is very complex and includes the evolution of the materials of interest as an aerosol within the ever changing local atmospheric motion. Wind patterns, however, are complex and difficult to model. They depend not only on local surface conditions and topology but on the global meteorological conditions. This paper presents an algebraic model to be used to simulate the vertical variation of the wind velocity and direction. The proposed model requires a minimum of input yet it qualitatively captures the mechanistic behavior of the wind with altitude. Results of the model are compared with both finite difference calculations and field data.

Lemmon, E.C.; Wiersma, G.B.; Bruns, D.A.

1986-04-01T23:59:59.000Z

123

Tidal Flow Turbulence Measurements  

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

max quire specification of a turbulence intensity, and it is a metric in the wind energy industry. For acoustic Dop surements, a noise-corrected expression of...

124

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

125

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

126

SPC Fire Weather Forecast Criteria Critical for temperature, wind, and relative humidity  

E-Print Network [OSTI]

the Energy Release Component (ERC) for fuel model G and 100 hr fuel moistures, which are available from: - Sustained winds 20 mph or greater (15 mph Florida) - Minimum relative humidity at or below regional thresholds (Fig. 1) - Temperatures above 50-60° F, depending on the season - Dry fuels (as defined below

127

What Are the Relative Roles of Heating and Cooling in Generating Solar Wind Temperature Anisotropies?  

E-Print Network [OSTI]

a combination of mechanisms of anisotropic heating (e.g., cyclotron-resonant heating and dissipation of kineticWhat Are the Relative Roles of Heating and Cooling in Generating Solar Wind Temperature, anisotropy-driven instabilities such as the cyclotron, mirror, and firehose instabilities limit the allowable

California at Berkeley, University of

128

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

129

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 Alfvén 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

130

Determining the influence of wind-wave breaking on the dissipation of the turbulent kinetic energy in the upper ocean and on the dependence of the turbulent kinetic energy on the stage of wind-wave development  

Science Journals Connector (OSTI)

New experimental data that make it possible to explain and predict the observed variability of turbulent-energy dissipation in the upper ocean are discussed. ... For this purpose, the dependence of the energy dis...

S. A. Kitaigorodskii

2009-06-01T23:59:59.000Z

131

Evidence for Inhomogeneous Heating in the Solar Wind  

Science Journals Connector (OSTI)

Solar wind observations and magnetohydrodynamic (MHD) simulations are used to probe the nature of turbulence heating. In particular, the electron heat flux, electron temperature, and ion temperature in the solar wind are studied using ACE and Wind data. These heating diagnostics are also compared with MHD simulation estimates of the local dissipation density. Coherent structures, which are sources of inhomogeneity and intermittency in MHD turbulence, are found to be associated with enhancements in every heating-related diagnostic. This supports the hypothesis that significant inhomogeneous heating occurs in the solar wind, connected with current sheets that are dynamically generated by MHD turbulence. Indeed, a subset of these coherent current sheets might be candidates for magnetic reconnection. However, the specific kinetic mechanisms that heat and accelerate particles within these structures require further study.

K. T. Osman; W. H. Matthaeus; A. Greco; S. Servidio

2011-01-01T23:59:59.000Z

132

Similarity Equations for Wind and Temperature Profiles in the Radix Layer, at the Bottom of the Convective Boundary Layer  

Science Journals Connector (OSTI)

In the middle of the convective boundary layer, also known as the mixed layer, is a relatively thick region where wind speed and potential temperature are nearly uniform with height. Below this uniform layer (UL), wind speed decreases to zero at ...

Edi Santoso; Roland Stull

2001-06-01T23:59:59.000Z

133

Fluctuating wind power penetration as limited by frequency standard.  

E-Print Network [OSTI]

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

Luo, Changling, 1980-

2005-01-01T23:59:59.000Z

134

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

135

On Collisionless Electron-Ion Temperature Equilibration in the Fast Solar Wind  

E-Print Network [OSTI]

We explore a mechanism, entirely new to the fast solar wind, of electron heating by lower hybrid waves to explain the shift to higher charge states observed in various elements in the fast wind at 1 A.U. relative to the original coronal hole plasma. This process is a variation on that previously discussed for two temperature accretion flows by Begelman & Chiueh. Lower hybrid waves are generated by gyrating minor ions (mainly alpha-particles) and become significant once strong ion cyclotron heating sets in beyond 1.5 R_sun. In this way the model avoids conflict with SUMER electron temperature diagnostic measurements between 1 and 1.5 R_sun. The principal requirement for such a process to work is the existence of density gradients in the fast solar wind, with scale length of similar order to the proton inertial length. Similar size structures have previously been inferred by other authors from radio scintillation observations and considerations of ion cyclotron wave generation by global resonant MHD waves.

J. Martin Laming

2003-12-15T23:59:59.000Z

136

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 250°C (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

137

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

138

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

139

Relative drifts and temperature anisotropies of protons and $\\alpha$ particles in the expanding solar wind -- 2.5D hybrid simulations  

E-Print Network [OSTI]

We perform 2.5D hybrid simulations to investigate the origin and evolution of relative drift speeds between protons and $\\alpha$ particles in the collisionless turbulent low-$\\beta$ solar wind plasma. We study the generation of differential streaming by wave-particle interactions and absorption of turbulent wave spectra. Next we focus on the role of the relative drifts for the turbulent heating and acceleration of ions in the collisionless fast solar wind streams. The energy source is given by an initial broad-band spectrum of parallel propagating Alfv\\'en-cyclotron waves, which co-exists with the plasma and is self-consistently coupled to the perpendicular ion bulk velocities. We include the effect of a gradual solar wind expansion, which cools and decelerates the minor ions. This paper for the first time considers the combined effect of self-consistently initialized dispersive turbulent Alfv\\'enic spectra with differentially streaming protons and $\\alpha$ particles in the expanding solar wind outflows withi...

Maneva, Y G; Viñas, A

2014-01-01T23:59:59.000Z

140

Effects of Atmospheric Turbulence on Ballistic Testing  

Science Journals Connector (OSTI)

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

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

2008-05-01T23:59:59.000Z

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

The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI): Wind and Temperature Observations from the Ionospheric Connection Explorer (ICON)  

Science Journals Connector (OSTI)

We describe the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI), an instrument designed to measure thermospheric wind and temperature as part of the...

Englert, Christoph R; Harlander, John Mark; Brown, Charles M; Stephan, Andrew W; Makela, Jonathan J; Marr, Kenneth D; Immel, Thomas J

142

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

143

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

144

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.

145

Saturation wind power potential and its implications for wind energy  

Science Journals Connector (OSTI)

...and natural gas produce electricity...As such, wind turbines reduce direct...power, part I: Technologies, energy resources...arrays of wind turbines . J Wind Eng Ind...Yamada T (1982) Development of a turbulence...biofuel soot and gases, and methane...a single wind turbine intersects...

Mark Z. Jacobson; Cristina L. Archer

2012-01-01T23:59:59.000Z

146

A 3-D wind and temperature pre-processor for ATD models  

Science Journals Connector (OSTI)

Many atmospheric transport and dispersion models, based on various approaches and applied to different spatial scales, need 3-D meteorological fields referred to regular grid systems. Data generally available, however, cannot be directly employed because of their irregularities, inconsistencies, insufficient spatial detail or inadequate terrain representation. To fill the gap between these input requirements and the practical availability of data, a meteorological pre-processing system has been set up to provide 3-D fields on the basis of measured data available inside a selected area. The system allows, for a given area, (i) extraction and smoothing of elevation data from a digital elevation model; (ii) extraction of data from different meteorological databases; (iii) interactive selection and correction among the available measurements; (iv) interpolation in time of missing data; (v) data interpolation on a selected computational grid and (vi) reconstruction of 3-D temperature and mass-consistent wind fields. The whole system is outlined and a couple of applications at different spatial resolutions are presented.

M.G. Morselli; G. Calori; S. Finardi; C. Mazzola

1997-01-01T23:59:59.000Z

147

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

148

ARM - Wind Chill Calculations  

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

FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Wind Chill Calculations Wind Chill is the apparent temperature felt on the exposed human...

149

Simulation Analysis on Temperature Field for Doubly Fed Wind Generator Used in High Altitude Condition  

Science Journals Connector (OSTI)

In this paper, a 1.5 MW doubly fed wind generator was taken as an example. Its three-dimensional heat transfer physical model and mathematical model were established based on giving basic assumptions. Meanwhil...

Ding Shuye; Ge Yunzhong; Lü Xiangping

2012-01-01T23:59:59.000Z

150

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations  

Science Journals Connector (OSTI)

The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current region of the Southern Ocean using the Weather Research and Forecasting (WRF) Model and the U.S. Navy Coupled Ocean–Atmosphere Mesoscale ...

Natalie Perlin; Simon P. de Szoeke; Dudley B. Chelton; Roger M. Samelson; Eric D. Skyllingstad; Larry W. O’Neill

2014-11-01T23:59:59.000Z

151

Wind Mixing and Restratification in a Lake near the Temperature of Maximum Density  

Science Journals Connector (OSTI)

The cooling of a freshwater take provides an opportunity for studying wind mixing and restratification under the peculiar conditions associated with a density maximum. The concepts are explored using a mixing-layer model that incorporates both ...

David M. Farmer; Eddy Carmack

1981-11-01T23:59:59.000Z

152

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.

153

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

E-Print Network [OSTI]

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

Stanford University

154

Characteristics of 50–200-m Winds and Temperatures Derived from an Iowa Tall-Tower Network  

Science Journals Connector (OSTI)

Limitations in skill of wind speed forecasts lead to conservative bids of wind-plant production in the day-ahead energy market and usually to an underutilization of wind resources. Improvements are needed in understanding wind characteristics in ...

Renee A. Walton; Eugene S. Takle; William A. Gallus Jr.

2014-10-01T23:59:59.000Z

155

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

156

Simulation and analysis of a multi-order imaging Fabry–Perot interferometer for the study of thermospheric winds and temperatures  

Science Journals Connector (OSTI)

We describe an analysis procedure for estimating the thermospheric winds and temperatures from the multi-order two-dimensional (2D) interferograms produced by an imaging Fabry–Perot...

Makela, Jonathan J; Meriwether, John W; Huang, Yiyi; Sherwood, Peter J

2011-01-01T23:59:59.000Z

157

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

158

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

159

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

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

atmosphere contains large-scale turbulence struc- tures that propagate through the wind turbines and wind farms and influence wake motion. Over the course of a day, the wind...

160

Free and forced tropical variability: role of the wind-evaporation-sea surface temperature (WES) feedback  

E-Print Network [OSTI]

. : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 11 3 Spatial distribution of the ocean mixed layer depth used in the Slab Ocean Model. : : : : : : : : : : : : : : : : : : : : : : : : : : : : 22 4 Annual mean (a) SST (contour interval: 2 K) and (b) latent heat ux (contour interval: 40 W/m2...) as simulated in CCM3-SOM. : : : : 27 5 Annual mean (a) surface winds and (b) convective precipitation (contour interval: 2 mm/day) as simulated in CCM3-SOM. : : : : : : 28 6 Di erence in annual mean (a) SST (contour interval: 0.2 K): WES-o -SOM - CCM3-SOM...

Mahajan, Salil

2009-05-15T23:59:59.000Z

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.


161

Low-altitude atmospheric turbulence around an airport  

E-Print Network [OSTI]

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

Cass, Stanley Dale

2012-06-07T23:59:59.000Z

162

Effects of turbulence model on convective heat transfer of coolant flow in a prismatic very high temperature reactor core  

SciTech Connect (OSTI)

The existing study of Spall et al. shows that only {nu}{sup 2}-f turbulence model well matches with the experimental data of Shehata and McEligot which were obtained under strongly heated gas flows. Significant over-predictions in those literatures were observed in the convective heat transfer with the other famous turbulence models such as the k-{epsilon} and k-{omega} models. In spite of such good evidence about the performance of the{nu}{sup 2}-f model, the application of the {nu}{sup 2}-f model to the thermo-fluid analysis of a prismatic core is very rare. In this paper, therefore, the convective heat transfer of the coolant flow in a prismatic core has been investigated using the {nu}{sup 2}-f model. Computational fluid dynamics (CFD) calculations have been carried out for the typical unit cell geometry of a prismatic fuel column with typical operating conditions of prismatic designs. The tested Reynolds numbers of the coolant flow are 10,000, 20,000, 30,000 and 50,000. The predicted Nusselt numbers with the {nu}{sup 2}-f model are compared with the results by the other turbulence models (k-{epsilon} and SST) as well as the empirical correlations. (authors)

Lee, S. N.; Tak, N. I.; Kim, M. H.; Noh, J. M. [Korea Atomic Energy Research Inst., Daedeok-daero 989-11, Yuseong-gu, Daejeon (Korea, Republic of)

2012-07-01T23:59:59.000Z

163

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

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

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

164

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

165

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

166

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

167

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

SciTech Connect (OSTI)

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

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

2009-12-01T23:59:59.000Z

168

CHAPTER ____ THE AIR-WATER INTERFACE: TURBULENCE  

E-Print Network [OSTI]

.g. from paper mills. The desorption of dissolved substances, like PCBs, from inland and coastal water at an unsheared air-water interface, i.e., a situation in which the winds are light and the fluid motions category, we consider situations with significant wind shear at the surface. In this case, the turbulence

California at Santa Barbara, University of

169

NREL Software Models Performance of Wind Plants (Fact Sheet)...  

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

effects of weather patterns, turbulence, and complex terrain on the performance of wind turbines and plants. SOWFA simulates fluid dynam- ics on scales from regional weather to...

170

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

SciTech Connect (OSTI)

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

Hodgin, C.R.

1982-01-01T23:59:59.000Z

171

Environmental impact of wind energy  

Science Journals Connector (OSTI)

One purpose of wind turbines is to provide pollution-free electric power at a reasonable price in an environmentally sound way. In this focus issue the latest research on the environmental impact of wind farms is presented. Offshore wind farms affect the marine fauna in both positive and negative ways. For example, some farms are safe havens for porpoises while other farms show fewer harbor porpoises even after ten years. Atmospheric computer experiments are carried out to investigate the possible impact and resource of future massive installations of wind turbines. The following questions are treated. What is the global capacity for energy production by the wind? Will the added turbulence and reduced wind speeds generated by massive wind farms cool or heat the surface? Can wind farms affect precipitation? It is also shown through life-cycle analysis how wind energy can reduce the atmospheric emission of eight air pollutants. Finally, noise generation and its impact on humans are studied.

J Mann; J Teilmann

2013-01-01T23:59:59.000Z

172

Effect of grid size on building wind according to a computation fluid dynamics simulation  

Science Journals Connector (OSTI)

Skyscrapers negatively impact the environment by creating gusty winds, known as building winds, which are the result of descending turbulences ... air by tall buildings. Usually, a building wind impact assessment...

Jae-Cheol Kim; Kyoo-Seock Lee

2011-02-01T23:59:59.000Z

173

Characterizing the Fluctuations of Wind Power Production by Multi-time Statistics  

Science Journals Connector (OSTI)

The fluctuations of electrical energy, generated by wind turbines, reflect the interaction between the turbulent wind field and a complex technical system. In ... article we study time series of the integrated wind

Oliver Kamps

2014-01-01T23:59:59.000Z

174

Wind energy  

Science Journals Connector (OSTI)

Wind energy is rapidly growing. In 2006 the installed generating capacity in the world increased by 25%, a growth rate which has more or less been sustained during the last decade. And there is no reason to believe that this growth will slow significantly in the coming years. For example, the United Kingdom's goal for installed wind turbines by 2020 is 33 GW up from 2 GW in 2006, an average annual growth rate of 22% over that period. More than half of all turbines are installed in Europe, but United States, India and lately China are also rapidly growing markets. The cradle of modern wind energy was set by innovative blacksmiths in rural Denmark. Now the wind provides more than 20% of the electrical power in Denmark, the industry has professionalized and has close ties with public research at universities. This focus issue is concerned with research in wind energy. The main purposes of research in wind energy are to: decrease the cost of power generated by the wind; increase the reliability and predictability of the energy source; investigate and reduce the adverse environmental impact of massive deployment of wind turbines; build research based educations for wind energy engineers. This focus issue contains contributions from several fields of research. Decreased costs cover a very wide range of activities from aerodynamics of the wind turbine blades, optimal site selection for the turbines, optimization of the electrical grid and power market for a fluctuating source, more efficient electrical generators and gears, and new materials and production techniques for turbine manufacturing. The United Kingdom recently started the construction of the London Array, a 1 GW off-shore wind farm east of London consisting of several hundred turbines. To design such a farm optimally it is necessary to understand the chaotic and very turbulent flow downwind from a turbine, which decreases the power production and increases the mechanical loads on other nearby turbines. Also addressed within the issue is how much conventional power production can be replaced by the ceaseless wind, with the question of how Greece's target of 29% renewables by 2020 is to be met efficiently. Other topics include an innovative way to determine the power curve of a turbine experimentally more accurately, the use of fluid dynamics tools to investigate the implications of placing vortex generators on wind turbine blades (thereby possibly improving their efficiency) and a study of the perception of wind turbine noise. It turns out that a small but significant fraction of wind turbine neighbours feel that turbine generated noise impairs their ability to rest. The annoyance is correlated with a negative attitude towards the visual impact on the landscape, but what is cause and effect is too early to say. As mentioned there is a rush for wind turbines in many countries. However, this positive development for the global climate is currently limited by practical barriers. One bottleneck is the difficulties for the sub-suppliers of gears and other parts to meet the demand. Another is the difficulties to meet the demand for engineers specialized in wind. For that reason the Technical University of Denmark (DTU) recently launched the world's first Wind Energy Masters Program. Here and elsewhere in the world of wind education and research we should really speed up now, as our chances of contributing to emission free energy production and a healthier global climate have never been better. Focus on Wind Energy Contents The articles below represent the first accepted contributions and further additions will appear in the near future. Wind turbines—low level noise sources interfering with restoration? Eja Pedersen and Kerstin Persson Waye On the effect of spatial dispersion of wind power plants on the wind energy capacity credit in Greece George Caralis, Yiannis Perivolaris, Konstantinos Rados and Arthouros Zervos Large-eddy simulation of spectral coherence in a wind turbine wake A Jimenez, A Crespo, E Migoya and J Garcia How to improve the estimation of

Jakob Mann; Jens Nørkær Sørensen; Poul-Erik Morthorst

2008-01-01T23:59:59.000Z

175

A commotion over turbulence  

Science Journals Connector (OSTI)

... calculations) of dimensionless parameters of the reactor setup9. This has led to the IFS/PPPL model, named after the main institutions involved in its development. The basis for this ... other components besides the turbulence-induced diffusivity. Dorland and Kotschen-reuther have combined the IFS/PPPL diffusivity model with an assumed prescription for the density evolution and the boundary temperatures, ...

Benjamin A. Carreras

1997-01-23T23:59:59.000Z

176

Plasma turbulence  

SciTech Connect (OSTI)

The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

1998-07-01T23:59:59.000Z

177

Blandford MTA Tower Wind Monitoring This document provides information not repeated in the monthly wind monitoring  

E-Print Network [OSTI]

on a regular basis. The logger samples wind speed and direction once every two seconds. These are then combined applicable): wind speed, wind speed standard deviation, wind direction, temperature, and solar insolation. F1 ranges applied for high and low wind speeds. A wind direction standard Blandford MTA Tower Wind

Massachusetts at Amherst, University of

178

Marion Meteorological Tower Wind Monitoring This document provides information not repeated in the monthly wind monitoring  

E-Print Network [OSTI]

. The logger samples wind speed and direction once every two seconds. These are then combined into 10-minute): wind speed, wind speed standard deviation, wind direction, temperature, and solar insolation. F1 > TF1 applied for high and low wind speeds. A wind direction standard Marion Met Tower Wind Monitoring #12

Massachusetts at Amherst, University of

179

Ion Heating in Inhomogeneous Expanding Solar Wind Plasma: The Role of Parallel and Oblique Ion-Cyclotron Waves  

E-Print Network [OSTI]

Remote sensing observations of coronal holes show that heavy ions are hotter than protons and their temperature is anisotropic. In-situ observations of fast solar wind streams provide direct evidence for turbulent Alfv\\'en wave spectrum, left-hand polarized ion-cyclotron waves, and He$^{++}$ -- proton drift in the solar wind plasma, which can produce temperature anisotropies by resonant absorption and perpendicular heating of the ions. Furthermore, the solar wind is expected to be inhomogeneous on decreasing scales approaching the Sun. We study the heating of solar wind ions in inhomogeneous plasma with a turbulent spectrum of Alfv\\'enic fluctuations and drift with a 2.5D hybrid code. We include the expansion of the solar wind in an inhomogeneous plasma background, combined with the effects of a turbulent wave spectrum and of an initial ion drift. We study the influence of these effects on the perpendicular ion heating and cooling and on the spectrum of the magnetic fluctuations in the inhomogeneous backgroun...

Ozak, N; Viñas, A -F

2014-01-01T23:59:59.000Z

180

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

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

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

182

Resolved Turbulence Characteristics in Large-Eddy Simulations Nested within Mesoscale Simulations Using the Weather Research and Forecasting Model  

Science Journals Connector (OSTI)

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

Jeff Mirocha; Branko Kosovi?; Gokhan Kirkil

2014-02-01T23:59:59.000Z

183

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

184

Studies of temperature change in the mesosphere using OHemission  

E-Print Network [OSTI]

13 2.2. Energy level 14 2.3. Population of rotational level 16 2.4. Intensities of OH emission 18 3 on mesospheric temperature change 68 7.3. Turbulence and negative ions in mesosphere 69 7.4. Estimating the wind of the global warming. The OH (6-2) bands have been observed at a site close to Skibotn in northern Norway (69

Kassie, Endawoke Yizengaw

185

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

186

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

187

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

188

Offshore winds using remote sensing techniques  

Science Journals Connector (OSTI)

Ground-based remote sensing instruments can observe winds at different levels in the atmosphere where the wind characteristics change with height: the range of heights where modern turbine rotors are operating. A six-month wind assessment campaign has been made with a LiDAR (Light Detection And Ranging) and a SoDAR (Sound Detection and Ranging) on the transformer/platform of the world's largest offshore wind farm located at the West coast of Denmark to evaluate their ability to observe offshore winds. The high homogeneity and low turbulence levels registered allow the comparison of LiDAR and SoDAR with measurements from cups on masts surrounding the wind farm showing good agreement for both the mean wind speed and the longitudinal component of turbulence. An extension of mean wind speed profiles from cup measurements on masts with LiDAR observations results in a good match for the free sectors at different wind speeds. The log-linear profile is fitted to the extended profiles (averaged over all stabilities and roughness lengths) and the deviations are small. Extended profiles of turbulence intensity are also shown for different wind speeds up to 161 m. Friction velocities and roughness lengths calculated from the fitted log-linear profile are compared with the Charnock model which seems to overestimate the sea roughness for the free sectors.

Alfredo Peña; Charlotte Bay Hasager; Sven-Erik Gryning; Michael Courtney; Ioannis Antoniou; Torben Mikkelsen; Paul Sørensen

2007-01-01T23:59:59.000Z

189

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

190

Numerical Tokamak Turbulence calculations on the CRAY T3E  

Science Journals Connector (OSTI)

Full cross section calculations of ion-temperature-gradient-driven turbulence with Landau closure are being carried out as part of the Numerical Tokamak Turbulence Project, one of the U. S. Department of Energy's Phase II Grand Challenges. To include ... Keywords: PVM, fusion energy, parallel computing, t3e, turbulence

V. E. Lynch; J-N. Leboeuf; B. A. Carreras; J. D. Alvarez; L. Garcia

1997-11-01T23:59:59.000Z

191

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

192

Mean and peak wind loads on heliostats  

SciTech Connect (OSTI)

Mean and peak wind loads on flat rectangular or circular heliostats were measured on models in a boundary layer wind tunnel which included an atmospheric surface layer simulation. Horizontal and vertical forces, moments about horizontal axes at the ground level and at the centerline of the heliostat, and the moment about the vertical axis through the heliostat center were measured. Results showed that loads are higher than predicted from results obtained in a uniform, low-turbulence flow due to the presence of turbulence. Reduced wind loads were demonstrated for heliostats within a field of heliostats and upper bound curves were developed to provide preliminary design coefficients.

Peterka, J.A.; Tan, Z.; Cermak, J.E.; Bienkiewicz, B.

1989-05-01T23:59:59.000Z

193

Turbulent equipartitions in two dimensional drift convection  

SciTech Connect (OSTI)

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

Isichenko, M.B.; Yankov, V.V. [Univ. of California, Santa Barbara, CA (United States). Inst. for Theoretical Physics

1995-07-25T23:59:59.000Z

194

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

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

2012-01-01T23:59:59.000Z

195

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

196

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

197

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

198

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

199

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

200

A comparison of weak-turbulence and PIC simulations of weak electron-beam plasma interaction  

E-Print Network [OSTI]

Quasilinear theory has long been used to treat the problem of a weak electron beam interacting with plasma and generating Langmuir waves. Its extension to weak-turbulence theory treats resonant interactions of these Langmuir waves with other plasma wave modes, in particular ion-sound waves. These are strongly damped in plasma of equal ion and electron temperatures, as sometimes seen in, for example, the solar corona and wind. Weak turbulence theory is derived in the weak damping limit, with a term describing ion-sound wave damping then added. In this paper we use the EPOCH particle-in-cell code to numerically test weak turbulence theory for a range of electron-ion temperature ratios. We find that in the cold ion limit the results agree well, but increasing ion temperature the three-wave resonance becomes broadened in proportion to the ion-sound wave damping rate. This may be important in, for example, the theory of solar radio bursts, where the spectrum of Langmuir waves is critical. Additionally we establish...

Ratcliffe, Heather; Rozenan, Mohammed B Che; Nakariakov, Valery

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.


201

Song of the Wind  

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

Song of the Wind Song of the Wind Nature Bulletin No. 318-A October 26, 1968 Forest Preserve District of Cook County Richard B. Ogilvie, President Roland F. Eisenbeis, Supt. of Conservation SONG OF THE WIND The wind is simply air in motion. Air has substance like wood or water, it has pressure, it can acquire heat and hold a temperature, and it can travel from place to place.... The air which affects our lives is a layer seven or eight miles thick, called the troposphere, which is next to the earth. This air has pressure (14.7 pounds per square inch at sea level) and when various factors, one of which is temperature, cause changes in this pressure, the air starts moving. We cannot see it. We can hear it. The song of the wind is the most wonderful music on earth, and at times the most terrifying in its angry moments.

202

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

203

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

204

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

205

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

206

wind energy  

National Nuclear Security Administration (NNSA)

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

207

Enhanced Dispersion from Tall Stacks Near Modern Wind Mills  

Science Journals Connector (OSTI)

Dispersion modeling of emissions from tall stacks is often done with regulatory models, based on the Gaussian plume concept. When the plumes of tall stacks are influenced by the turbulence of nearby wind mills, t...

J. J. Erbrink; Luc Verhees

2014-01-01T23:59:59.000Z

208

Wind Energy  

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

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

209

Potential climatic impacts and reliability of large-scale offshore wind farms  

Science Journals Connector (OSTI)

The vast availability of wind power has fueled substantial interest in this renewable energy source as a potential near-zero greenhouse gas emission technology for meeting future world energy needs while addressing the climate change issue. However, in order to provide even a fraction of the estimated future energy needs, a large-scale deployment of wind turbines (several million) is required. The consequent environmental impacts, and the inherent reliability of such a large-scale usage of intermittent wind power would have to be carefully assessed, in addition to the need to lower the high current unit wind power costs. Our previous study (Wang and Prinn 2010 Atmos. Chem. Phys. 10 2053) using a three-dimensional climate model suggested that a large deployment of wind turbines over land to meet about 10% of predicted world energy needs in 2100 could lead to a significant temperature increase in the lower atmosphere over the installed regions. A global-scale perturbation to the general circulation patterns as well as to the cloud and precipitation distribution was also predicted. In the later study reported here, we conducted a set of six additional model simulations using an improved climate model to further address the potential environmental and intermittency issues of large-scale deployment of offshore wind turbines for differing installation areas and spatial densities. In contrast to the previous land installation results, the offshore wind turbine installations are found to cause a surface cooling over the installed offshore regions. This cooling is due principally to the enhanced latent heat flux from the sea surface to lower atmosphere, driven by an increase in turbulent mixing caused by the wind turbines which was not entirely offset by the concurrent reduction of mean wind kinetic energy. We found that the perturbation of the large-scale deployment of offshore wind turbines to the global climate is relatively small compared to the case of land-based installations. However, the intermittency caused by the significant seasonal wind variations over several major offshore sites is substantial, and demands further options to ensure the reliability of large-scale offshore wind power. The method that we used to simulate the offshore wind turbine effect on the lower atmosphere involved simply increasing the ocean surface drag coefficient. While this method is consistent with several detailed fine-scale simulations of wind turbines, it still needs further study to ensure its validity. New field observations of actual wind turbine arrays are definitely required to provide ultimate validation of the model predictions presented here.

Chien Wang; Ronald G Prinn

2011-01-01T23:59:59.000Z

210

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

211

Quantitative visualization of compressible turbulent shear flows using condensate-enhanced Rayleigh scattering  

E-Print Network [OSTI]

was based on laser scattering from particles of H2O or CO2 condensate that form in the wind tunnel nozzleQuantitative visualization of compressible turbulent shear flows using condensate-enhanced Rayleigh

Miles, Richard

212

Turbulent flow in graphene  

E-Print Network [OSTI]

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

Kumar S. Gupta; Siddhartha Sen

2009-11-03T23:59:59.000Z

213

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

214

Wind Mills  

Science Journals Connector (OSTI)

Over 5,000 years ago, the ancient Egyptians used wind to sail ships on the Nile River. While the proliferation of water mills was in full swing, windmills appeared to harness more inanimate energy by employing wind

J. S. Rao

2011-01-01T23:59:59.000Z

215

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...

216

Wind Power  

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

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

217

Wind Power  

Science Journals Connector (OSTI)

For off-shore wind energy, it is not economically profitable to locate wind turbines in waters with depths larger than about 40 m. For this reason, some floating turbine prototypes are being tested, which can be ...

Ricardo Guerrero-Lemus; José Manuel Martínez-Duart

2013-01-01T23:59:59.000Z

218

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

219

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

220

Nonlinear wave evolution in the expanding solar wind  

Science Journals Connector (OSTI)

We report here on a numerical model allowing direct numerical simulations of magnetohydrodynamic fluctuations advected by the expanding solar wind. We show that the expansion of the plasma delays and possibly freezes the turbulent evolution, but that it also triggers the nonlinear evolution of otherwise stable (Alfvén) waves, which can thus release their energy in the wind.

Roland Grappin; Marco Velli; André Mangeney

1993-04-05T23:59:59.000Z

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

Wind energy  

Science Journals Connector (OSTI)

...is approximately 4.5-6.01 for onshore wind farms. The price for offshore wind farms is estimated to be 50% higher. For comparison...visually intrusive. The visual impact of offshore wind farms quickly diminishes with distance and 10km...

2007-01-01T23:59:59.000Z

222

‘Chinook winds.’  

Science Journals Connector (OSTI)

...of south-easterly winds, which blow over the...Ocean, from which the winds come, can at this season...freezing-point. The wind well known in the Alps as the foehn is another example of...result is complicated by local details; regions of...

George M. Dawson

1886-01-08T23:59:59.000Z

223

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

224

Lidar-based Research and Innovation at DTU Wind Energy – a Review  

Science Journals Connector (OSTI)

As wind turbines during the past decade have increased in size so have the challenges met by the atmospheric boundary-layer meteorologists and the wind energy society to measure and characterize the huge-volume wind fields surpassing and driving them. At the DTU Wind Energy test site "Østerild" for huge wind turbines, the hub-height of a recently installed 8 MW Vestas V164 turbine soars 143 meters up above the ground, and its rotor of amazing 164 meters in diameter make the turbine tips flicker 225 meters into the sky. Following the revolution in photonics-based telecommunication at the turn of the Millennium new fibre-based wind lidar technologies emerged and DTU Wind Energy, at that time embedded within Rise National Laboratory, began in collaboration with researchers from wind lidar companies to measure remote sensed wind profiles and turbulence structures within the atmospheric boundary layer with the emerging, at that time new, all-fibre-based 1.55 ? coherent detection wind lidars. Today, ten years later, DTU Wind Energy routinely deploys ground-based vertical profilers instead of met masts for high-precision measurements of mean wind profiles and turbulence profiles. At the departments test site "Høvsøre" DTU Wind Energy also routinely calibrate and accredit wind lidar manufactures wind lidars. Meanwhile however, new methodologies for power curve assessment based on ground-based and nacelle based lidars have also emerged. For improving the turbines power curve assessments and for advancing their control with feed-forward wind measurements experience has also been gained with wind lidars installed on turbine nacelles and integrated into the turbines rotating spinners. A new mobile research infrastructure WindScanner.dk has also emerged at DTU Wind Energy. Wind and turbulence fields are today scanned from sets of three simultaneously in space and time synchronized scanning lidars. One set consists of three fast scanning continuous-wave based wind lidars (short-range system), and another consisting of three synchronized pulsed wind lidar systems (long-range system). Today, wind lidar profilers and WindScanners are routinely deployed and operated during field tests and measurement campaigns. Lidars have been installed and operated from ground, on offshore platforms, and also as scanning lidars integrated in operating turbines. As a result, wind profiles and also detailed 3D scanning of wind and turbulence fields have been achieved: 1) of the free wind aloft, 2) over complex terrain, 3) at coastal ranges with land-sea interfaces, 4) offshore, 5) in turbine inflow induction zone, and 6) of the complex and turbulent flow fields in the wakes inside wind parks.

T Mikkelsen

2014-01-01T23:59:59.000Z

225

The Origin of Non-Maxwellian Solar Wind Electron Velocity Distribution Function: Connection to Nanoflares in the Solar Corona  

E-Print Network [OSTI]

The formation of the observed core-halo feature in the solar wind electron velocity distribution function is a long-time puzzle. In this letter based on the current knowledge of nanoflares we show that the nanoflare-accelerated electron beams are likely to trigger a strong electron two-stream instability that generates kinetic Alfv\\'en wave and whistler wave turbulence, as we demonstrated in a previous paper. We further show that the core-halo feature produced during the origin of kinetic turbulence is likely to originate in the inner corona and can be preserved as the solar wind escapes to space along open field lines. We formulate a set of equations to describe the heating processes observed in the simulation and show that the core-halo temperature ratio of the solar wind is insensitive to the initial conditions in the corona and is related to the core-halo density ratio of the solar wind and to the quasi-saturation property of the two-stream instability at the time when the exponential decay ends. This rel...

Che, H

2014-01-01T23:59:59.000Z

226

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

227

NREL: Wind Research - Computer-Aided Engineering Tools  

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

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

228

Wind Blog  

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

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

229

Research papers Observations over an annual cycle and simulations of wind-forced  

E-Print Network [OSTI]

Research papers Observations over an annual cycle and simulations of wind-forced oscillations near Turbulence Model (GOTM) 1-D simulations of diurnal wind forcing, including the first order coast breeze Diurnal wind Namibia Benguela current a b s t r a c t Sea breezes are characteristic features

Gille, Sarah T.

230

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

231

Ris DTU Dec.3 2009WindScanner.eu 1 Ris DTU, Technical University of Denmark  

E-Print Network [OSTI]

engulfing today's and tomorrows huge on and offshore wind turbines. - a brig less RI for renewable energy IWES (onshore sites, Alpha Ventus ­ FINO 1- 3 offshore) · Norway: SINTEF (offshore technology, floatingScanner.eu Envisioned new RI European Centre for Wind Energy Research in Atmospheric Turbulent Flow "The Wind

232

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 für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Max-Planck/Princeton Center for Plasma Physics (Germany); Navarro, Alejandro Bañón, E-mail: alejandro.banon.navarro@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Jenko, Frank, E-mail: frank.jenko@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Max-Planck/Princeton Center for Plasma Physics (Germany)

2014-07-15T23:59:59.000Z

233

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

234

Influence of non-Gaussian wind characteristics on wind turbine extreme response  

Science Journals Connector (OSTI)

Abstract The wind turbulence inflows specified in current wind turbine design standards and turbine response simulation tools are usually modeled as stationary random Gaussian processes. Field measurement data, however, suggest that wind turbulence in complex terrain exhibits non-Gaussian characteristics. This study presents a comprehensive investigation on extreme response of operational and parked wind turbines to non-Gaussian wind field. The non-Gaussian wind fields with specified non-Gaussian statistics and power spectral characteristics are generated using translation process theory and spectral representation method. The wind turbine response time histories at each wind speed bin are simulated. The turbine response statistical moments influenced by the non-Gaussian wind inflow are examined. The extreme response distributions conditional on wind speeds are determined from the simulation data using global maxima method and random process model method. The overall extreme response distribution is then calculated by further integrating the distribution of mean wind speed, which is used to quantify the extreme responses with various mean recurrence intervals (MRIs). The results showed that the non-Gaussian characteristics of wind inflows can result in noticeably larger extremes of blade root edgewise and tower base fore-aft bending moments of operational turbine, and blade root flapwise bending moment of parked turbine. The responses with larger \\{MRIs\\} are more sensitive to the non-Gaussian characteristics of wind inflows. The responses of parked turbine are less sensitive to non-Gaussian, especially, the tower base side-to-side bending moment is almost not affected by non-Gaussian. New insights on the determination of extreme response distribution from random process method are also presented focusing on a better modeling of the response distribution tail.

Kuangmin Gong; Xinzhong Chen

2014-01-01T23:59:59.000Z

235

The effect of wind speed and direction and surrounding maize on hybrid ventilation in a dairy cow building in Denmark  

Science Journals Connector (OSTI)

Abstract This study evaluated the effect of wind speed and direction and surrounding maize field on the air exchange rate (ACH) and indoor air velocity in a dairy cow building with hybrid ventilation, which combined auto-controlled natural and partial mechanical pit ventilation. The standard k ? ? turbulence model and standard wall function were applied in CFD modeling with extension of capability to account for the aerodynamics effect of surrounding maize plant canopy in the wind domain by using user defined functions (UDF). This extended model was validated by on-site measured velocities and temperatures. A reasonably good agreement was found between simulated and measured results. The wind speed influenced ACH greatly while modeling the maize field had little effect on ACH with low wind speed. With wind speed of 3.86 m s?1 in validation case, modeling the maize field reduced total ACH by 24%, ACH via bottom openings on the sidewall by 89.7% and air speed measured upwind by 71%. The results revealed that the plant canopy had the most significant effect on ACH through the opening on the sidewall. With the variation of wind direction from 0° to 90°, the difference of ACH could be 60%.

L. Rong; D. Liu; E.F. Pedersen; G. Zhang

2015-01-01T23:59:59.000Z

236

Turbulent Erosion Of Persistent Cold-Air Pools: Numerical Simulations  

Science Journals Connector (OSTI)

High-resolution idealized numerical simulations are used to examine the turbulent removal of cold-air pools commonly observed in mountain valleys and basins. A control simulation with winds aloft increasing from 0.5 to 20 m s-1 over 20 h combined ...

Neil P. Lareau; John D. Horel

237

Kinematics of Turbulence Convected by a Random Wave Field  

Science Journals Connector (OSTI)

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

J. L. Lumley; E. A. Terray

1983-11-01T23:59:59.000Z

238

Wind Power Forecasting  

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

Retrospective Reports 2011 Smart Grid Wind Integration Wind Integration Initiatives Wind Power Forecasting Wind Projects Email List Self Supplied Balancing Reserves Dynamic...

239

Interfaces and inhomogeneous turbulence  

Science Journals Connector (OSTI)

...argued that these local distortion mechanisms...meteorological model WRF [58]. This is...anabatic and katabatic winds. The thermal forcing...wind, the cross-wind horizontal breeze...This leads to a local vortex form with...the length of the wind tunnel where the...10], using the local RMS velocity and...

2011-01-01T23:59:59.000Z

240

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

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

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

242

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

243

Self Consistent Models of the Solar Wind  

E-Print Network [OSTI]

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

Cranmer, Steven R

2010-01-01T23:59:59.000Z

244

Wind Powering America: Wind Events  

Wind Powering America (EERE)

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

245

Amplification of ion-acoustic turbulence upon electron-cyclotron heating of plasma  

Science Journals Connector (OSTI)

In this paper, we present the results of the study of ion-acoustic turbulence upon electron-cyclotron heating of low-temperature plasma in a TAU-...

G. M. Batanov; L. V. Kolik; D. V. Malakhov…

2009-10-01T23:59:59.000Z

246

Turbulence avoidance: An alternate explanation of turbulence ...  

Science Journals Connector (OSTI)

ABSTRACT: Field observations supporting the hypothesis that wind-driven ... tend not to have the resolving power to distinguish an alternative hypothesis: that

247

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

248

Wyoming Wind Power Project (generation/wind)  

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

Wind Power > Generation Hydro Power Wind Power Monthly GSP BPA White Book Dry Year Tools Firstgov Wyoming Wind Power Project (Foote Creek Rim I and II) Thumbnail image of wind...

249

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

250

Offshore Wind Power USA  

Broader source: Energy.gov [DOE]

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

251

Argonne National Laboratory Develops Extreme-Scale Wind Farm Simulation Capabilities  

Broader source: Energy.gov [DOE]

Researchers at DOE's Argonne National Laboratory are developing a computational simulation tool to conduct studies of complex flow and wind turbine interactions in large land-based and offshore wind farms that will improve wind plant design and reduce the levelized cost of energy. Simulations on a wind-plant-scale require accurate simultaneous resolution of multiple flow scales, from mesoscale weather to turbine-blade scale turbulence, which presents special demands on the computational solver efficiency and requires extreme scalability.

252

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

253

A Minnesota Blizzard Provides Insight into Utility-Scale Wind Turbine Wakes  

Broader source: Energy.gov [DOE]

Starting in 2012, researchers tried placing spotlights downwind from the 2.5-megawatt (MW) wind turbine in Rosemount, Minnesota. The research team was attempting to study turbulent airflow around a turbine in the field.

254

Near-surface wind estimates using statistics from a planetary boundary-layer model  

Science Journals Connector (OSTI)

This paper shows the possibilities of a procedure for estimating near-surface wind statistics, by means of the numerical integration of a simple boundary-layer model with a second-order turbulent closure. Stan...

J. C. Labraga

1988-04-01T23:59:59.000Z

255

offshore wind farm  

Science Journals Connector (OSTI)

offshore wind farm, wind farm [‘Wind park’ which one may find on the ... engineers and should not be used. A wind farm consists of a network of wind turbines] ? Windkraftanlage f, Windpark m; Offshore

2014-08-01T23:59:59.000Z

256

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"

257

Design Wind Speed  

Science Journals Connector (OSTI)

Wind is characterized by various different parameters. They include the following items: (1) wind speed, such as the mean wind speed and maximum instantaneous wind speed; (2) wind direction such as the azimuth di...

Yozo Fujino; Kichiro Kimura; Hiroshi Tanaka

2012-01-01T23:59:59.000Z

258

4A.5 DERIVING TURBULENT KINETIC ENERGY DISSIPATION RATE WITHIN CLOUDS USING GROUND BASED 94 GHZ RADAR  

E-Print Network [OSTI]

distribution of the optical and microphysics properties. Turbulence is also directly linked to the life cycle is to perform spectral analysis on air- craft data (for instance Gultepe and Starr (1995)) or from ground based. The variance 1 #12;v 2 of the mean wind is an indicator of the kinetic energy in turbulent scales

Hogan, Robin

259

A climatic dataset of ocean vertical turbulent mixing coefficient based on real energy sources  

Science Journals Connector (OSTI)

Using data on wind stress, significant height of combined wind waves and swell, potential temperature, salinity and seawater velocity, as well as objectively-analyzed in situ temperature and salinity, we establis...

Yu Zhang; YiHua Lin; RuiXin Huang

2014-10-01T23:59:59.000Z

260

Wind Powering America: New England Wind Forum  

Wind Powering America (EERE)

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

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

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

262

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

263

Wind News  

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

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

264

PERPENDICULAR ION HEATING BY REDUCED MAGNETOHYDRODYNAMIC TURBULENCE  

SciTech Connect (OSTI)

Recent theoretical studies argue that the rate of stochastic ion heating in low-frequency Alfvén-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 Alfvén 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

265

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

266

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...

267

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

268

Large-eddy simulation of offshore wind farm  

Science Journals Connector (OSTI)

A hybrid numerical capability is developed for the simulation of offshore wind farms in which large-eddy simulation is performed for the wind turbulence and a potential flow based method is used for the simulation of the ocean wave field. The wind and wave simulations are dynamically coupled. The effect of wind turbines on the wind field is represented by an actuator disk model. This study focuses on the effect of wind-seas and the turbine motion is treated as negligibly small. A variety of fully-developed and fetch-limited wind-sea conditions and turbine spacings are considered in the study. Statistical analyses are performed for the simulation results with a focus on the mean wind profile kinetic energy budget in the wind field and the wind turbine power extraction rate. The results indicate that the waves have appreciable effect on the wind farm performance. The wind turbines obtain a higher wind power extraction rate under the fully developed wind-sea condition compared with that under the fetch-limited condition. This higher extraction rate is caused by the faster propagating waves and the lower sea-surface resistance on the wind when the wind-seas are fully developed. The wave-induced difference can be as high as 8% with the commonly used turbine spacing in commercial land-based wind farms s x = 7 (with s x being the ratio of streamwise turbine spacing to the turbine diameter). Such level of difference is noteworthy considering the previous understanding that direct wave-induced disturbance to the wind field decays exponentially away from wave surface.

2014-01-01T23:59:59.000Z

269

Observations of Edge Turbulence  

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

Edge Turbulence Edge Turbulence near the X-point of Alcator C-Mod APS-2007 (1) J.L. Terry, S.J. Zweben*, B. LaBombard, I. Cziegler, O. Grulke + , D.P. Stotler* MIT - Plasma Science and Fusion Center *Princeton Plasma Physics Laboratory + MPI for Plasma Physics, EURATOM Assoc., Greifswald, Germany American Physical Society - Div. of Plasma Physics Orlando, FL Nov. 12 - Nov. 16, 2007 APS-2007 (2) Background and Motivation for "Xpt-region" View Strong edge turbulence has been observed in nearly all magnetic confinement devices. Desire predictive capability Most previous measurements made near outboard midplane where the turbulence has the following main features: - generation is ballooning-like (absent at inboard midplane, etc.) - filaments/blobs moves radially outward with some poloidal motion

270

ARM - Measurement - Atmospheric turbulence  

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

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

271

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

272

NREL: Wind Research - Wind Resource Assessment  

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

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

273

New England Wind Forum: Wind Power Technology  

Wind Powering America (EERE)

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

274

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

275

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

276

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

277

Balancing of Wind Power.  

E-Print Network [OSTI]

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

Ülker, Muhammed Akif

2011-01-01T23:59:59.000Z

278

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

279

WINDExchange: Learn About Wind  

Wind Powering America (EERE)

Curricula & Teaching Materials Resources Learn About Wind Learn about how wind energy generates power; where the best wind resources are; how you can own, host, partner...

280

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

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

Wind modelling based on wind input data conditions using Weibull distribution  

Science Journals Connector (OSTI)

Weibull distribution can be used to model the wind speed distribution at a particular site and hence, it can help in wind resource assessment (WRA) of a site. By calculating the shape (k) and scale (c) parameters for Weibull distribution, the wind speed frequency curve for a site can be made. Once this wind speed distribution for site is determined, it can be convolved with the power curve for a wind turbine and the annual energy output from the site can be determined. This paper presents how the Weibull distribution is used to determine the wind speed distribution for Vadravadra site in Gau Island of Fiji and how closely the annual energy output from the modelled wind speed distribution matches with the annual energy output using the actual wind speed distribution. It also presents how k is related to the turbulence intensity for a site; how the c is related to the annual mean wind speed and how a formula for estimating c is derived at a new height.

R.D. Prasad; R.C. Bansal; M. Sauturaga

2009-01-01T23:59:59.000Z

282

Global invariants in ideal magnetohydrodynamic turbulence  

SciTech Connect (OSTI)

Magnetohydrodynamic (MHD) turbulence is an important though incompletely understood factor affecting the dynamics of many astrophysical, geophysical, and technological plasmas. As an approximation, viscosity and resistivity may be ignored, and ideal MHD turbulence may be investigated by statistical methods. Incompressibility is also assumed and finite Fourier series are used to represent the turbulent velocity and magnetic field. The resulting model dynamical system consists of a set of independent Fourier coefficients that form a canonical ensemble described by a Gaussian probability density function (PDF). This PDF is similar in form to that of Boltzmann, except that its argument may contain not just the energy multiplied by an inverse temperature, but also two other invariant integrals, the cross helicity and magnetic helicity, each multiplied by its own inverse temperature. However, the cross and magnetic helicities, as usually defined, are not invariant in the presence of overall rotation or a mean magnetic field, respectively. Although the generalized form of the magnetic helicity is known, a generalized cross helicity may also be found, by adding terms that are linear in the mean magnetic field and angular rotation vectors, respectively. These general forms are invariant even in the presence of overall rotation and a mean magnetic field. We derive these general forms, explore their properties, examine how they extend the statistical theory of ideal MHD turbulence, and discuss how our results may be affected by dissipation and forcing.

Shebalin, John V. [Astromaterials Research Office, NASA Johnson Space Center, Houston, Texas 77058-3696 (United States)] [Astromaterials Research Office, NASA Johnson Space Center, Houston, Texas 77058-3696 (United States)

2013-10-15T23:59:59.000Z

283

New England Wind Forum: Wind Power Economics  

Wind Powering America (EERE)

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

284

New England Wind Forum: Large Wind  

Wind Powering America (EERE)

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

285

NREL: Wind Research - International Wind Resource Maps  

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

projections of wind resources worldwide. This allows for more accurate siting of wind turbines and has led to the recognition of higher class winds in areas where none were...

286

Advanced Hydraulic Wind Energy  

Science Journals Connector (OSTI)

The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems ... Keywords: wind, tide, energy, power, hydraulic

Jack A. Jones; Allan Bruce; Adrienne S. Lam

2013-04-01T23:59:59.000Z

287

WINDExchange: Wind Economic Development  

Wind Powering America (EERE)

help you analyze the economics of a small wind electric system and decide whether wind energy will work for you. Wind Energy Finance Online Calculator Wind Energy Finance developed...

288

Exploiting Wind Versus Coal  

Science Journals Connector (OSTI)

...be offset with turbine mass production...of installed turbines, more than the...Denmark have wind parks offshore, where winds...of installed turbines, more than the...Denmark have wind parks offshore, where winds...

Mark Z. Jacobson; Gilbert M. Masters

2001-08-24T23:59:59.000Z

289

NREL: Wind Research - Wind Energy Videos  

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

Wind Energy Videos The National Wind Technology Center (NWTC) is pleased to offer video presentations of its world-class capabilities, facilities, research areas, and personnel. As...

290

On the Degeneration of Turbulence at High Reynolds Numbers  

E-Print Network [OSTI]

Turbulent fluctuations in a fluid wind down at a certain rate once stirring has stopped. The role of the most basic parameter in fluid mechanics, the Reynolds number, in setting this decay rate is not generally known. This paper concerns the high-Reynolds-number limit of the process. In a wind-tunnel experiment that reached higher Reynolds numbers than ever before and covered more than two decades in the Reynolds number ($10^4 speed of the flow, $M$ the forcing scale, and $\

Sinhuber, Michael; Bewley, Gregory P

2014-01-01T23:59:59.000Z

291

wind power station  

Science Journals Connector (OSTI)

wind power station [It may consist of just one wind turbine or a network of windmills] ? Windkraftanlage

2014-08-01T23:59:59.000Z

292

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

293

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

294

Experimental study of vortex generators effects on low Reynolds number airfoils in turbulent flow  

Science Journals Connector (OSTI)

In the present work, we study the aerodynamic effects of triangular vortex generators, as passive flow control devices, placed on the upper surface of an airfoil submitted to a low Reynolds number turbulent flow. In the experiments, different configurations of those devices have been studied. An Eppler 387 airfoil was used. The tests were performed in a turbulent boundary layer wind tunnel using a two component aerodynamic balance and flow visualisation systems. Turbulent flow characterisation was made by means of hot wire anemometry. Calculations of local turbulent intensity as well as temporal and spatial turbulent scales were made. Vortex generators were located at 10% and 20% of the airfoil chord from the leading edge, modifying its angle of incidence refereed to the free stream. The results show changes in the aerodynamic section coefficients, C1, Cd and C1, for the different vortex generator configurations. Neither hysteresis effects, nor leading edge bubbles were found in the experiments.

Juan Sebastián Delnero; Julio Marañon Di Leo; Mauricio Ezequiel Camocardi; Mariano A. Martinez; Jorge L. Colman Lerner

2012-01-01T23:59:59.000Z

295

NREL: Wind Research - Small Wind Turbine Webinars  

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

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

296

New England Wind Forum: Small Wind  

Wind Powering America (EERE)

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

297

NREL: Wind Research - Small Wind Turbine Development  

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

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

298

Turbines and turbulence  

Science Journals Connector (OSTI)

... Will wind turbines wreck the environment? Last month, the South China Morning Post published a news story ... dismissive official quoted probably has a point. There is no solid scientific evidence that wind turbines can trigger major changes in rainfall. And given Nature's conversations with atmospheric modellers ...

2010-12-22T23:59:59.000Z

299

Neutrino-driven wind and wind termination shock in supernova cores  

E-Print Network [OSTI]

The neutrino-driven wind from a nascent neutron star at the center of a supernova expands into the earlier ejecta of the explosion. Upon collision with this slower matter the wind material is decelerated in a wind termination shock. By means of hydrodynamic simulations in spherical symmetry we demonstrate that this can lead to a large increase of the wind entropy, density, and temperature, and to a strong deceleration of the wind expansion. The consequences of this phenomenon for the possible r-process nucleosynthesis in the late wind still need to be explored in detail. Two-dimensional models show that the wind-ejecta collision is highly anisotropic and could lead to a directional dependence of the nucleosynthesis even if the neutrino-driven wind itself is spherically symmetric.

A. Arcones; L. Scheck; H. -Th. Janka

2006-12-21T23:59:59.000Z

300

Transport during Turbulent Heating in a Tokamak  

Science Journals Connector (OSTI)

A model for the University of Texas turbulent torus is described. The prediction of the model shows a strong skin effect, and is in agreement with the experimental data if one saturates the Buneman instability by using the electron-trapping condition and the ionsound instability by using the anomalous collision frequency ?A?10-5(TeTi)(uve)?pe, which correlates with ion tail formation. An interpretation of the laser-scattering temperature measurements is proposed.

P. L. Mascheroni

1977-07-25T23:59:59.000Z

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.


301

Turbulence radiation interaction modeling in hydrocarbon pool fire simulations  

SciTech Connect (OSTI)

The importance of turbulent fluctuations in temperature and species concentration in thermal radiation transport modeling for combustion applications is well accepted by the radiation transport and combustion communities. A number of experimental and theoretical studies over the last twenty years have shown that fluctuations in the temperature and species concentrations may increase the effective emittance of a turbulent flame by as much as 50% to 300% over the value that would be expected from the mean temperatures and concentrations. With the possibility of such a large effect on the principal mode of heat transfer from a fire, it is extremely important for fire modeling efforts that turbulence radiation interaction be well characterized and possible modeling approaches understood. Toward this end, this report seeks to accomplish three goals. First, the principal turbulence radiation interaction closure terms are defined. Second, an order of magnitude analysis is performed to understand the relative importance of the various closure terms. Finally, the state of the art in turbulence radiation interaction closure modeling is reviewed. Hydrocarbon pool fire applications are of particular interest in this report and this is the perspective from which this review proceeds. Experimental and theoretical analysis suggests that, for this type of heavily sooting flame, the turbulent radiation interaction effect is dominated by the nonlinear dependence of the Planck function on the temperature. Additional effects due to the correlation between turbulent fluctuations in the absorptivity and temperature may be small relative to the Planck function effect for heavily sooting flames. This observation is drawn from a number of experimental and theoretical discussions. Nevertheless, additional analysis and data is needed to validate this observation for heavily sooting buoyancy dominated plumes.

BURNS,SHAWN P.

1999-12-01T23:59:59.000Z

302

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

303

NREL: Wind Research - Offshore Wind Research  

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

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

304

NREL: Wind Research - Site Wind Resource Characteristics  

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

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

305

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

306

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

307

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

308

An Exploration of Wind Energy & Wind Turbines | Department of...  

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

An Exploration of Wind Energy & Wind Turbines An Exploration of Wind Energy & Wind Turbines Below is information about the student activitylesson plan from your search. Grades...

309

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...

310

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...

311

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

312

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

Office of Environmental Management (EM)

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

313

Wind for Schools Project Power System Brief, Wind Powering America...  

Wind Powering America (EERE)

Wind Powering America Fact Sheet Series Energy Efficiency & Renewable Energy Wind for Schools Project Power System Brief Wind for Schools Project Power System Brief Wind for...

314

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

315

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

316

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

317

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

318

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

319

Sandia National Laboratories: Wind Resources  

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

EnergyWind Resources Wind Resources Comments are closed. Renewable Energy Wind Energy Wind Plant Optimization Test Site Operations & Maintenance Safety: Test Facilities Capital...

320

Sandia National Laboratories: wind energy  

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

Wind Energy Manufacturing Lab Helps Engineers Improve Wind Power On November 15, 2011, in Energy, News, Partnership, Renewable Energy, Wind Energy Researchers at the Wind Energy...

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

Wind Energy | Department of Energy  

Office of Environmental Management (EM)

Wind Energy Wind Energy Below are resources for Tribes on wind energy technologies. 2012 Market Report on Wind Technologies in Distributed Applications Includes a breakdown of...

322

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

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

2012-10-01T23:59:59.000Z

323

NREL: Wind Research - Small Wind Turbine Research  

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

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

324

Wind Vision Wind Farm | Open Energy Information  

Open Energy Info (EERE)

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

325

High Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

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

326

Resolving the generation of starburst winds in Galaxy mergers  

Science Journals Connector (OSTI)

......Galactic wind thermal+metal...temperatures). The maps show the images...ISM, i.e. mass per logarithmic...with outflow velocity v r - 100s1), the wind/outflow...we show the wind mass above different...absolute radial velocity cuts to highlight......

Philip F. Hopkins; Dusan Keres; Norman Murray; Lars Hernquist; Desika Narayanan; Christopher C. Hayward

2013-01-01T23:59:59.000Z

327

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

328

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

Open Energy Info (EERE)

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

329

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

Open Energy Info (EERE)

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

330

Wind farm land suitability indexing using multi-criteria analysis  

Science Journals Connector (OSTI)

Wind farm siting can be considered as Multi Criteria Decision Making (MCDM) problem that consists of set of alternative locations and set of selection criteria. This study applied multi-criteria decision making approach using Analytical Hierarchy Process with Ordered Weigh Averaging AHP-OWA aggregation function to derive wind farm land suitability index and classification under Geographical Information System (GIS) environment. Linguistic quantifier’s version of AHP-OWA aggregation function was used to classify lands based on their suitability for wind farm installation. Different selection criteria were considered including economical (distance to road, terrain slope), social (urban area), environmental (historical locations, wildlife and natural reserves) and technical (wind power density, energy demand matching, percentage of sustainable wind, turbulence intensity, sand dunes). A case study of the proposed approach is implemented and presented for Oman.

Sultan Al-Yahyai; Yassine Charabi; Adel Gastli; Abdullah Al-Badi

2012-01-01T23:59:59.000Z

331

EXPERIMENTAL INVESTIGATION OF TURBULENT HEAT TRANSFER OF HIGH PRANDTL NUMBER FLUID FLOW UNDER STRONG MAGNETIC FIELD  

E-Print Network [OSTI]

EXPERIMENTAL INVESTIGATION OF TURBULENT HEAT TRANSFER OF HIGH PRANDTL NUMBER FLUID FLOW UNDER to the heat transfer characteristic: Flibe is a high Prandtl number fluid. For high Prandtl number fluid, there is a severe limitation of temperature window due to its high melting point. The turbulent heat transfer is

Abdou, Mohamed

332

Wind pump systems  

Science Journals Connector (OSTI)

The application of wind mills for water pumping is of lesser importance ... it is useful to discuss this type of wind energy application in a wind energy book targeted at development and planning...

Prof. Dr.-Ing. Robert Gasch; Prof. Dr.-Ing. Jochen Twele

2012-01-01T23:59:59.000Z

333

NREL: Wind Research - Testing  

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

the National Wind Technology Center (NWTC) support the installation and testing of wind turbines that range in size from 400 watts to 5.0 megawatts. Engineers provide wind...

334

Fixed Offshore Wind Turbines  

Science Journals Connector (OSTI)

In this chapter, a perspective of offshore wind farms, applied concepts for fixed offshore wind turbines, and related statistics are given. One example of a large wind farm, which is successfully operating, is st...

Madjid Karimirad

2014-01-01T23:59:59.000Z

335

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

336

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

337

Modeling Turbulent Flow  

National Nuclear Security Administration (NNSA)

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

338

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 Å Ellingsen; Per-Åge Krogstad

2014-02-10T23:59:59.000Z

339

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

340

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

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

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

342

Wind farm noise  

Science Journals Connector (OSTI)

Arrays of small wind turbines recently coined as “wind farms” offer several advantages over single larger wind turbines producing the same electrical power. Noise source characteristics of wind farms are also different from those associated with a single wind turbine. One?third octave band noise measurements from 2 Hz to 10 kHz have been made and will be compared to measurements of noise produced by a single large wind turbine. [J. R. Balombin Technical Memorandum 81486.

Gregory C. Tocci; Brion G. Koning

1981-01-01T23:59:59.000Z

343

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

344

NREL: Wind Research - Offshore Wind Resource Characterization  

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

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

345

NREL: Wind Research - Midsize Wind Turbine Research  

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

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

346

Diablo Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

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

347

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

348

Wind Turbine Tribology Seminar  

Broader source: Energy.gov [DOE]

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

349

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

350

Northern Wind Farm  

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

a draft environmental assessment (EA) on the proposed interconnection of the Northern Wind Farm (Project) in Roberts County, near the city of Summit, South Dakota. Northern Wind,...

351

Wind Program News  

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

eerewindwind-program-news en EERE Leadership Celebrates Offshore Wind in Maine http:energy.goveerearticleseere-leadership-celebrates-offshore-wind-maine

352

British wind band music.  

E-Print Network [OSTI]

??I have chosen to be assessed as an interpreter and conductor of British wind band music from the earliest writings for wind band up to,… (more)

Jones, GO

2005-01-01T23:59:59.000Z

353

WINDExchange: Wind Energy Ordinances  

Wind Powering America (EERE)

Wind Energy Ordinances Federal, state, and local regulations govern many aspects of wind energy development. The exact nature of the project and its location will largely drive the...

354

Wind Program: WINDExchange  

Wind Powering America (EERE)

Version Bookmark and Share WINDExchange logo WINDExchange is the U.S. Department of Energy (DOE) Wind Program's platform for disseminating credible information about wind...

355

WINDExchange: Siting Wind Turbines  

Wind Powering America (EERE)

Wind Wildlife Institute (AWWI) facilitates timely and responsible development of wind energy, while protecting wildlife and wildlife habitat. AWWI was created and is sustained by...

356

WINDExchange: Collegiate Wind Competition  

Wind Powering America (EERE)

& Teaching Materials Resources Collegiate Wind Competition The U.S. Department of Energy (DOE) Collegiate Wind Competition challenges interdisciplinary teams of undergraduate...

357

Quantum ghost imaging through turbulence  

SciTech Connect (OSTI)

We investigate the effect of turbulence on quantum ghost imaging. We use entangled photons and demonstrate that for a specific experimental configuration the effect of turbulence can be greatly diminished. By decoupling the entangled photon source from the ghost-imaging central image plane, we are able to dramatically increase the ghost-image quality. When imaging a test pattern through turbulence, this method increases the imaged pattern visibility from V=0.15{+-}0.04 to 0.42{+-}0.04.

Dixon, P. Ben; Howland, Gregory A.; Howell, John C. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Chan, Kam Wai Clifford [Rochester Optical Manufacturing Company, Rochester, New York 14606 (United States); O'Sullivan-Hale, Colin; Rodenburg, Brandon [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Hardy, Nicholas D.; Shapiro, Jeffrey H. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Simon, D. S.; Sergienko, A. V. [Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States); Boyd, R. W. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

2011-05-15T23:59:59.000Z

358

Filtering Turbulent Sparsely Observed Geophysical Flows  

Science Journals Connector (OSTI)

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

John Harlim; Andrew J. Majda

2010-04-01T23:59:59.000Z

359

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

360

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.


361

Sandia National Laboratories: Wind Energy  

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

specialprogramsslide5 windplantoptslide4 rotorinnovationslide3 offshorewindslide2 Materialsslide1 Wind Energy Wind Plant Optimization Materials,...

362

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

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

ProductsCloud-Scale Vertical Velocity and Turbulent ProductsCloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Site(s) NSA General Description Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May

363

Alfvén 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 Alfvén 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 Alfvén 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 Alfvén wave generated nonlinearly by a collision between counterpropagating Alfvén 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

364

Global simulations of magnetorotational turbulence – II. Turbulent energetics  

Science Journals Connector (OSTI)

......Importantly, as we are using an ideal MHD simulation, this shows that...construct a simplified energy flow diagram, which is shown in Fig...the heart of self-sustaining MHD turbulence in accretion discs. Figure 14. Energy flow diagram for turbulence in a global disc......

E. R. Parkin

2014-01-01T23:59:59.000Z

365

NONRESONANT INTERACTION OF CHARGED ENERGETIC PARTICLES WITH LOW-FREQUENCY NONCOMPRESSIVE TURBULENCE: NUMERICAL SIMULATION  

SciTech Connect (OSTI)

A new method for simulating the three-dimensional dynamics of charged energetic particles in very broadband noncompressive magnetic turbulence is introduced. All scales within the primary inertial range of the turbulence observed in the solar wind near 1 AU are now included for the independent computations of both the particle dynamics and the turbulent magnetic field lines (MFLs). While previous theories of resonant particle pitch-angle (PA) scattering and transport in interplanetary magnetic fields had favored interpreting the observed depletions in the electron PA distributions (PADs) around 90 Degree-Sign PA as evidence of poor scattering at low PA cosines, the computed particle dynamics reveal a very different reality. The MFL directions now vary on many scales, and the PADs are depleted around 90 Degree-Sign PA due to nonresonant filtering of the particles that propagate at too large an angle to the local magnetic field. Rather than being too weak, the scattering through 90 Degree-Sign PA is actually so strong that the particles (electrons and protons/ions) are reflected and trapped in the turbulent magnetic fields. While the low-frequency nonresonant turbulence produces ubiquitous magnetic traps that only let through particles with the most field-aligned velocities, higher-frequency near-gyroscale turbulence, when present, enhances particle transport by allowing the particles to navigate between magnetic traps. Finally, visualizing both particle trajectories and MFLs in the very same turbulence reveals a powerful tool for understanding the effects of the turbulent fields on the particle dynamics and cross-field transport. Some cross-field-line scattering, strongly amplified by MFL dispersal, results in a strong cross-field scattering of the particles. From this visualization, it also appears that near-gyroscale turbulence, previously known as gyroresonant turbulence, does not resonantly interact with the particles. The interaction between particles and fields at or near the gyroscale, though potentially strong, does not actually involve the periodic driving of a true resonance.

Ragot, B. R. [Helio Research, P.O. Box 1414, Nashua, NH 03061 (United States)

2012-10-20T23:59:59.000Z

366

GROWTH OF A LOCALIZED SEED MAGNETIC FIELD IN A TURBULENT MEDIUM  

SciTech Connect (OSTI)

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

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

2012-11-10T23:59:59.000Z

367

Large eddy simulation for predicting turbulent heat transfer in gas turbines  

Science Journals Connector (OSTI)

...predicting turbulent heat transfer in gas turbines Danesh K. Tafti Long He K. Nagendra...of propulsion and power generation gas turbines. Accurate prediction of blade metal...compressed bypass air and allow higher turbine inlet temperature, increasing fuel efficiency...

2014-01-01T23:59:59.000Z

368

West Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

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

369

www.cesos.ntnu.no Author Centre for Ships and Ocean Structures Offshore Wind Turbine Operation  

E-Print Network [OSTI]

1 www.cesos.ntnu.no Author ­ Centre for Ships and Ocean Structures Offshore Wind Turbine Operation icing for offshore Wind Turbines ? · Wherever there is sea icing ! · Temperature bellow zero degree Structures Outline · Introduction · Wind Turbine Operational Conditions · Wind Turbine Operation under

Nørvåg, Kjetil

370

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

371

Howard County- Wind Ordinance  

Broader source: Energy.gov [DOE]

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

372

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 wave energy under the influence of wind shear (Booker and Bretherton, 1967). A critical level, if it exists, is the level at which the horizontal phase velocity of the wave equals the mean wind speed. If a wave passes through a criti- cal level...

Incrocci, Thomas Paul

2012-06-07T23:59:59.000Z

373

WIND DATA REPORT Ragged Mt Maine  

E-Print Network [OSTI]

...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions........................................................................................................... 9 Monthly Average Wind Speeds

Massachusetts at Amherst, University of

374

Turbulent Magnetic Reconnection Near a  

E-Print Network [OSTI]

Turbulent Magnetic Reconnection Near a 3D Magnetic Null C. S. Ng Space Science Center Institute for the Study of Earth, Oceans, and Space University of New Hampshire, Durham, NH 03824 #12;Turbulent Magnetic Reconnection Near a 3D Magnetic Null C. S. Ng, chung-sang.ng@unh.edu, Space Science Center, Institute

Ng, Chung-Sang

375

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

376

Wind Powering America  

Wind Powering America (EERE)

These news items are notable additions These news items are notable additions to the Wind Powering America Web site. The Wind Powering America Web site reports recent national and state wind market changes by cataloging wind activities such as wind resource maps, small wind consumer's guides, local wind workshops, news articles, and publications in the areas of policy, public power, small wind, Native Americans, agricultural sector, economic development, public lands, and schools. en-us julie.jones@nrel.gov (Julie Jones) http://www.windpoweringamerica.gov/images/wpa_logo_sm.jpg Wind Powering America http://www.windpoweringamerica.gov/ Nominate an Electric Cooperative for Wind Power Leadership Award by January 15 http://www.windpoweringamerica.gov/filter_detail.asp?itemid=4076 http://www.windpoweringamerica.gov/filter_detail.asp?itemid=4076 Mon, 16

377

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

Open Energy Info (EERE)

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

378

A wind speed retrieval algorithm by combining 6 and 10 GHz data from Advanced Microwave Scanning Radiometer: Wind speed inside hurricanes  

Science Journals Connector (OSTI)

A wind speed retrieval algorithm was developed using 6 and ... aboard AQUA, for the purpose of retrieving wind speed inside rainstorms, primarily hurricanes and typhoons. ... because the brightness temperature se...

Akira Shibata

2006-06-01T23:59:59.000Z

379

New England Wind Forum: New England Wind Resources  

Wind Powering America (EERE)

New England Wind Forum About the New England Wind Forum New England Wind Energy Education Project Historic Wind Development in New England State Activities Projects in New England Building Wind Energy in New England Wind Resources Wind Power Technology Economics Markets Siting Policy Technical Challenges Issues Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share New England Wind Resources Go to the Vermont wind resource map. Go to the New Hampshire wind resource map. Go to the Maine wind resource map. Go to the Massachusetts wind resource map. Go to the Connecticut wind resource map. Go to the Rhode Island wind resource map. New England Wind Resource Maps Wind resources maps of Connecticut, Massachusetts, Maine, New Hampshire, Rhode Island, and Vermont.

380

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

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

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

382

INTERCHANGE RECONNECTION IN A TURBULENT CORONA  

SciTech Connect (OSTI)

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

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

2012-10-10T23:59:59.000Z

383

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

384

NREL: Wind Research - WindPACT  

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

WindPACT WindPACT The Wind Partnerships for Advanced Component Technology (WindPACT) studies were conducted to assist industry by testing innovative components, such as advanced blades and drivetrains, to lower the cost of energy. Specific goals included: Foster technological advancements to reduce 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 necessary to achieve objectives of cost and size for future turbines Identify and solve technological hurdles that may block industry from taking advantage of promising technology Design, fabricate, and test selected advanced components to prove their viability Support wind industry through transfer of technology from

385

Wind | Department of Energy  

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

Wind Wind Wind America is home to one of the largest and fastest growing wind markets in the world. Watch the video to learn more about the latest trends in the U.S. wind power market and join us this Thursday, August 8 at 3 pm ET for a Google+ Hangout on wind energy in America. The United States is home to one of the largest and fastest growing wind markets in the world. To stay competitive in this sector, the Energy Department invests in wind projects, both on land and offshore, to advance technology innovations, create job opportunities and boost economic growth. Moving forward, the U.S. wind industry remains a critical part of the Energy Department's all-of-the-above energy strategy to cut carbon pollution, diversify our energy economy and bring the next-generation of

386

Offshore Wind Projects | Department of Energy  

Office of Environmental Management (EM)

Offshore Wind Projects Offshore Wind Projects This report covers the Wind and Water Power Program's offshore wind energy projects from fiscal years 2006 to 2014. Offshore Wind...

387

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

388

NREL: Wind Research - Offshore Wind Research  

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

standards Third-party design verification of innovative floating and fixed-bottom wind turbines NREL's standards and testing capabilities address the need to validate our...

389

Characterization of wind noise by the boundary layer meteorology  

Science Journals Connector (OSTI)

The fluctuations in pressure generated by turbulent motions of the atmospheric boundary layer are a principal noise source in outdoor acoustic measurements. The mechanics of wind noise involve not only stagnation pressure fluctuations at the sensor but also shearing and self-interaction of turbulence throughout the flow particularly at low frequencies. The contributions of these mechanisms can be described by the boundary-layer meteorology. An experiment was conducted at the National Wind Institute's 200-meter meteorological tower located outside Lubbock Texas in the Llano Estacado region. For two days a 44-element 400-meter diameter array of unscreened NCPA-UMX infrasound sensors recorded wind noise continuously while the tower and a Doppler SODAR measured vertical profiles of the boundary layer. Analysis of the fluctuating pressure with the meteorological data shows that the statistical structure of wind noise depends on both mean velocity distribution and buoyant stability. The root-mean-square pressure exhibits distinct scalings for stable and unstable stratification. Normalization of the pressure power spectral density depends on the outer scales. In stable conditions the kurtosis of the wind noise increases with Reynolds number. Measures of noise intermittency are explored with respect to the meteorology.

2014-01-01T23:59:59.000Z

390

Memory effects in turbulent transport  

E-Print Network [OSTI]

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

Alexander Hubbard; Axel Brandenburg

2008-11-17T23:59:59.000Z

391

Kinetic dissipation and anisotropic heating in a turbulent collisionless plasma  

E-Print Network [OSTI]

The kinetic evolution of the Orszag-Tang vortex is studied using collisionless hybrid simulations. In the magnetohydrodynamic regime this vortex leads rapidly to broadband turbulence. Significant differences from MHD arise at small scales, where the fluid scale energy dissipates into heat almost exclusively through the magnetic field because the protons are decoupled from the magnetic field. Although cyclotron resonance is absent, the protons heat preferentially in the plane perpendicular to the mean field, as in the corona and solar wind. Effective transport coefficients are calculated.

Parashar, T N; Cassak, P A; Matthaeus, W H

2008-01-01T23:59:59.000Z

392

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

393

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

394

NREL: Wind Research - @NWTC Newsletter  

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

NREL Investigates the Logistics of Transporting and Installing Bigger, Taller Wind Turbines NREL Plays Founding, Developmental Role in Major Wind Journal Boosting Wind Plant...

395

2012 Wind Technologies Market Report  

E-Print Network [OSTI]

Department of Energy (DOE). 2008. 20% Wind Energy by2030: Increasing Wind Energy’s Contribution to U.S.Integrating Midwest Wind Energy into Southeast Electricity

Wiser, Ryan

2014-01-01T23:59:59.000Z

396

Sandia National Laboratories: Wind Power  

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

Wind Energy Staff On March 24, 2011, in Wind Energy On November 10, 2010, in Wind Plant Opt. Rotor Innovation Materials, Reliability & Standards Siting & Barrier Mitigation...

397

Sandia National Laboratories: wind manufacturing  

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

manufacturing Wind Energy Manufacturing Lab Helps Engineers Improve Wind Power On November 15, 2011, in Energy, News, Partnership, Renewable Energy, Wind Energy Researchers at the...

398

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

399

NREL: Wind Research - Projects  

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

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

400

Wind power today  

SciTech Connect (OSTI)

This publication highlights initiatives of the US DOE`s Wind Energy Program. 1997 yearly activities are also very briefly summarized. The first article describes a 6-megawatt wind power plant installed in Vermont. Another article summarizes technical advances in wind turbine technology, and describes next-generation utility and small wind turbines in the planning stages. A village power project in Alaska using three 50-kilowatt turbines is described. Very brief summaries of the Federal Wind Energy Program and the National Wind Technology Center are also included in the publication.

NONE

1998-04-01T23:59:59.000Z

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.


401

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

402

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

403

Information theoretical characterization of turbulence  

Science Journals Connector (OSTI)

A method of describing turbulence in terms of dynamical connectivity in the wave-number space is proposed. The connectivity is quantified by the information theoretical quantities, i.e., mutual information and cross information flow rate. This method is applied to the analysis of two simple examples of turbulence in one spatial dimension. Although the examples have quite different physical origins, the information structures of the wave-number space turn out to be quite similar: The wave-number space consists of several regions generating information in different ways, and how information flows between these regions reflects the dynamical structure of turbulence.

K. Ikeda and K. Matsumoto

1989-05-08T23:59:59.000Z

404

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...

405

Women of Wind Energy Honor Wind Program Researchers | Department...  

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

Women of Wind Energy Honor Wind Program Researchers Women of Wind Energy Honor Wind Program Researchers August 1, 2013 - 2:54pm Addthis This is an excerpt from the Second Quarter...

406

The Wind of Variable C in M33  

E-Print Network [OSTI]

We discuss the spectrum of Var C in M33 obtained just before the onset of its current brightening and recent spectra during its present "eruption" or optically thick wind stage. These spectra illustrate the typical LBV transition in apparent spectral type or temperature that characterizes the classical LBV or S Dor-type variability. LBVs are known to have slow, dense winds during their maximum phase. Interestingly, Var C had a slow wind even during its hot, quiescent stage in comparison with the normal hot supergiants with similar temperatures. Its outflow or wind speeds also show very little change between these two states.

Humphreys, Roberta M; Gordon, Michael; Weis, Kerstin; Burggraf, Birgitta; Bomans, D J; Martin, John C

2014-01-01T23:59:59.000Z

407

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

408

Magnetic helicity signature produced by cross-field 2D turbulence  

SciTech Connect (OSTI)

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

Markovskii, S. A.; Vasquez, Bernard J. [Space Science Center, Institute for the Study of Earth, Oceans, and Space, and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)

2013-06-13T23:59:59.000Z

409

Magnetic helicity signature produced by cross-field 2D turbulence  

Science Journals Connector (OSTI)

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

2013-01-01T23:59:59.000Z

410

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

411

NREL: News Feature - NREL Software Tool a Boon for Wind Industry  

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

temperatures, and other variables alter the air flow and energy production at wind farms. Photo by Dennis Schroeder, NREL Wind energy is blowing away skeptics-it's so close to...

412

Bias Correction and Bayesian Model Averaging for Ensemble Forecasts of Surface Wind Direction  

Science Journals Connector (OSTI)

Wind direction is an angular variable, as opposed to weather quantities such as temperature, quantitative precipitation, or wind speed, which are linear variables. Consequently, traditional model output statistics and ensemble postprocessing ...

Le Bao; Tilmann Gneiting; Eric P. Grimit; Peter Guttorp; Adrian E. Raftery

2010-05-01T23:59:59.000Z

413

The Statistical Predictability of Surface Winds over Western and Central Canada  

Science Journals Connector (OSTI)

Multivariate linear regression is used to downscale reanalysis-based midtropospheric predictors (wind components and speed, temperature, and geopotential height) to historical wind observations at 44 surface weather stations during the four ...

Aaron M. R. Culver; Adam H. Monahan

2013-11-01T23:59:59.000Z

414

NREL: Wind Research - National Wind Technology Center  

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

Center Center The National Renewable Energy Laboratory's (NREL's) National Wind Technology Center (NWTC), located at the base of the foothills just south of Boulder, Colorado, is the nation's premier wind energy technology research facility. Built in 1993, the center provides an ideal environment for the development of advanced wind energy technologies. The goal of the research conducted at the center is to help industry reduce the cost of energy so that wind can compete with traditional energy sources, providing a clean, renewable alternative for our nation's energy needs. Research at the NWTC is organized under two main categories, Wind Technology Development and Testing and Operations. Illustration of the National Wind Technology Center's organization chart. Fort Felker is listed as the Center Director, with Mike Robinson, Deputy Center Director; Paul Veers, Chief Engineer, and Laura Davis and Dorothy Haldeman beneath him. The Associate Director position is empty. Beneath them is the Wind Technology Research and Development Group Manager, Mike Robinson; the Testing and Operations Group Manager, Dave Simms; and the Offshore Wind and Ocean Power Systems Acting Supervisor, Fort Felker.

415

Wind Rose Bias Correction  

Science Journals Connector (OSTI)

Wind rose summaries, which provide a basis for understanding and evaluating the climatological behavior of local wind, have a directional bias if a conventional method is used in their generation. Three techniques used to remove this bias are ...

Scott Applequist

2012-07-01T23:59:59.000Z

416

Surface Wind Direction Variability  

Science Journals Connector (OSTI)

Common large shifts of wind direction in the weak-wind nocturnal boundary layer are poorly understood and are not adequately captured by numerical models and statistical parameterizations. The current study examines 15 datasets representing a ...

Larry Mahrt

2011-01-01T23:59:59.000Z

417

GSA Wind Supply Opportunity  

Office of Environmental Management (EM)

Wind Supply Opportunity 1 2 3 Proposed Location * Size: 100-210 MegaWatts *Location: Bureau County, IL *Planned COD: December 2014 or 2015 *Site Control: 17,000 acres *Wind...

418

Scale Models & Wind Turbines  

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

Scale Models and Wind Turbines Grades: 5-8, 9-12 Topics: Wind Energy Owner: Kidwind Project This educational material is brought to you by the U.S. Department of Energy's Office of...

419

Distributed Wind 2015  

Broader source: Energy.gov [DOE]

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

420

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:/...

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

NREL: Wind Research - Awards  

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

Awards NREL has received many awards for its technical innovations in wind energy. In addition, the research conducted at the National Wind Technology Center (NWTC) at NREL has led...

422

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...

423

Wind Career Map  

K-12 Energy Lesson Plans and Activities Web site (EERE)

This wind career map explores an expanding universe of wind energy occupations, describing diverse jobs across the industry, charting possible progression between them, and identifying the high-quality training necessary to do them well.

424

WINDExchange: Wind Events  

Wind Powering America (EERE)

Sun, 15 Feb 2015 00:00:00 MST 2015 Iowa Wind Power Conference and Iowa Wind Energy Association Midwest Regional Energy Job Fair http:www.iowawindenergy.org...

425

WINDExchange: Wind Potential Capacity  

Wind Powering America (EERE)

area with a gross capacity factor1 of 35% and higher, which may be suitable for wind energy development. AWS Truepower LLC produced the wind resource data with a spatial...

426

Offshore wind metadata management  

Science Journals Connector (OSTI)

Offshore wind energy is gaining more and more attention from industry and research community due to its high potential in producing green energy and lowering price on electricity consumption. However, offshore wind is facing many challenges, and hence ...

Trinh Hoang Nguyen; Rocky Dunlap; Leo Mark; Andreas Prinz; Bjørn Mo Østgren; Trond Friisø

2014-10-01T23:59:59.000Z

427

2008 WIND TECHNOLOGIES MARKET REPORT  

E-Print Network [OSTI]

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

Bolinger, Mark

2010-01-01T23:59:59.000Z

428

How Do Wind Turbines Work?  

Broader source: Energy.gov [DOE]

Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.

429

WINDExchange: Wind Basics and Education  

Wind Powering America (EERE)

locate higher education and training programs. Learn about Wind Learn about how wind energy generates power; where the best wind resources are; how you can get wind power; and...

430

WINDExchange: What Is Wind Power?  

Wind Powering America (EERE)

animation to see how a wind turbine works or take a look inside. Wind power or wind energy describes the process by which the wind is used to generate mechanical power or...

431

The Wind at Our Backs  

Science Journals Connector (OSTI)

...uncertainty that chills U.S. wind farm development. He...serious challenge of siting wind turbines in the United States...a community college wind training program, and...and the nation's first offshore wind project near Nantucket...

Dan Reicher

2012-05-11T23:59:59.000Z

432

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.

433

Wind Energy Markets, 2. edition  

SciTech Connect (OSTI)

The report provides an overview of the global market for wind energy, including a concise look at wind energy development in key markets including installations, government incentives, and market trends. Topics covered include: an overview of wind energy including the history of wind energy production and the current market for wind energy; key business drivers of the wind energy market; barriers to the growth of wind energy; key wind energy trends and recent developments; the economics of wind energy, including cost, revenue, and government subsidy components; regional and national analyses of major wind energy markets; and, profiles of key wind turbine manufacturers.

NONE

2007-11-15T23:59:59.000Z

434

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

435

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

436

Offshore Wind Potential Tables  

Wind Powering America (EERE)

Offshore wind resource by state and wind speed interval within 50 nm of shore. Wind Speed at 90 m (ms) 7.0 - 7.5 7.5 - 8.0 8.0 - 8.5 8.5 - 9.0 9.0 - 9.5 9.5 - 10.0 >10.0 Total...

437

Offshore wind energy systems  

Science Journals Connector (OSTI)

Wind energy systems deployed in the shallow but windy waters of the southern North Sea have the potential to provide more than 20% of UK electricity needs. With existing experience of windmills, and of aircraft and offshore structures, such wind energy systems could be developed within a relatively short timescale. A preliminary assessment of the economics of offshore wind energy systems is encouraging.

P Musgrove

1978-01-01T23:59:59.000Z

438

Wind Turbine Competition Introduction  

E-Print Network [OSTI]

Wind Turbine Competition Introduction: The Society of Hispanic Professional Engineers, SHPE at UTK, wishes to invite you to participate in our first `Wind Turbine' competition as part of Engineer's Week). You will be evaluated by how much power your wind turbine generates at the medium setting of our fan

Wang, Xiaorui "Ray"

439

New England Wind Forum: New England Wind Projects  

Wind Powering America (EERE)

Projects in New England Building Wind Energy in New England Wind Resource Wind Power Technology Economics Markets Siting Policy Technical Challenges Issues Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share New England Wind Projects This page shows the location of installed and planned New England wind projects. Find windfarms, community-scale wind projects, customer-sited wind projects, small wind projects, and offshore wind projects. Read more information about how to use the Google Map and how to add your wind project to the map. Text version New England Wind Energy Projects Connecticut, East Canaan Wind Connecticut, Klug Farm Connecticut, Phoenix Press Connecticut, Wind Colebrook (South and North)

440

Photo of the Week: Eye-to-Eye with a Wind Turbine | Department of Energy  

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

Eye-to-Eye with a Wind Turbine Eye-to-Eye with a Wind Turbine Photo of the Week: Eye-to-Eye with a Wind Turbine August 7, 2013 - 10:35am Addthis At the National Renewables Energy Laboratory (NREL), scientists use the Insight Center Collaboration Room to examine and interact with their data. In this simulation, the room is converted into a virtual wind tunnel, allowing scientists to study the complex, turbulent flow fields around wind turbines. Pictured here, NREL Senior Scientist Kenny Gruchalla examines the velocity field surrounding a wind turbine, using a 3-D model projected onto the center's 16-by-8 foot wall. The simulation helps scientists better understand flow patterns, and further, how turbines can better avoid gearbox failures. Learn more about the Insight Center Collaboration Room. | Photo courtesy of Dennis Schroeder, NREL.

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

Digital simulation of 3D turbulence wind field of Sutong Bridge based on measured wind spectra  

Science Journals Connector (OSTI)

Time domain analysis is an essential implement to study the buffeting behavior of long-span bridges for it can consider the non-linear effect which is significant in long-span bridges. The prerequisite of time do...

Hao Wang; Zhou-hong Zong; Ai-qun Li; Teng Tong…

2012-02-01T23:59:59.000Z

442

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

443

4A.5 DERIVING TURBULENT KINETIC ENERGY DISSIPATION RATE WITHIN CLOUDS USING GROUND BASED 94 GHZ RADAR  

E-Print Network [OSTI]

distribution of the optical and microphysics properties. Turbulence is also directly linked to the life cycle is to perform spectral analysis on air­ craft data (for instance Gultepe and Starr (1995)) or from ground based is partitioned between different scales. The variance 1 #12; s v 2 of the mean wind is an indicator

Hogan, Robin

444

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

445

Understanding strategies for seed dispersal by wind under contrasting atmospheric conditions  

Science Journals Connector (OSTI)

...direction, air temperature, solar radiation and time...canopy turbulent kinetic energy (TKE) production rate...achieved as a result of flow obstacles such as vegetation...occurring 2 when incident solar radiation causes large...mechanical turbulent energy production. Fig. 1 shows...

S. Joseph Wright; Ana Trakhtenbrot; Gil Bohrer; Matteo Detto; Gabriel G. Katul; Nir Horvitz; Helene C. Muller-Landau; Frank A. Jones; Ran Nathan

2008-01-01T23:59:59.000Z

446

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....

447

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....

448

Turbulent flame speed for syngas at gas turbine relevant conditions  

Science Journals Connector (OSTI)

Modifications of conventional natural-gas-fired burners for operation with syngas fuels using lean premixed combustion is challenging due to the different physicochemical properties of the two fuels. A key differentiating parameter is the turbulent flame velocity, ST, commonly expressed as its ratio to the laminar flame speed, SL. This paper reports an experimental investigation of premixed syngas combustion at gas turbine like conditions, with emphasis on the determination of ST/SL derived as global fuel consumption per unit time. Experiments at pressures up to 2.0 MPa, inlet temperatures and velocities up to 773 K and 150 m/s, respectively, and turbulence intensity to laminar flame speed ratios, u?/SL, exceeding 100 are presented for the first time. Comparisons between different syngas mixtures and methane clearly show much higher ST/SL for the former fuel. It is shown that ST/SL is strongly dependent on preferential diffusive-thermal (PDT) effects, co-acting with hydrodynamic effects, even for very high u?/SL. ST/SL increases with rising hydrogen content in the fuel mixture and with increasing pressure. A correlation for ST/SL valid for all investigated fuel mixtures, including methane, is proposed in terms of turbulence properties (turbulence intensity and integral length scale), combustion properties (laminar flame speed and laminar flame thickness) and operating conditions (pressure and inlet temperature). The correlation captures effects of preferential diffusive-thermal and hydrodynamic instabilities.

S. Daniele; P. Jansohn; J. Mantzaras; K. Boulouchos

2011-01-01T23:59:59.000Z

449

Particle Heating by Alfvenic Turbulence in Hot Accretion Flows  

E-Print Network [OSTI]

Recent work on Alfvenic turbulence by Goldreich & Sridhar (1995; GS) suggests that the energy cascades almost entirely perpendicular to the local magnetic field. As a result, the cyclotron resonance is unimportant in dissipating the turbulent energy. Motivated by the GS cascade, we calculate the linear collisionless dissipation of Alfven waves with frequencies much less than the proton cyclotron frequency, but with perpendicular wavelengths of order the Larmor radius of thermal protons. In plasmas appropriate to hot accretion flows (proton temperature much greater than electron temperature) the dissipated Alfven wave energy primarily heats the protons. For a plasma with $\\beta \\lsim 5$, however, where $\\beta$ is the ratio of the gas pressure to the magnetic pressure, the MHD assumptions utilized in the GS analysis break down before most of the energy in Alfven waves is dissipated; how the cascade then proceeds is unclear. Hot accretion flows, such as advection dominated accretion flows (ADAFs), are expected to contain significant levels of MHD turbulence. This work suggests that, for $\\beta \\gsim 5$, the Alfvenic component of such turbulence primarily heats the protons. Significant proton heating is required for the viability of ADAF models. We contrast our results on particle heating in ADAFs with recent work by Bisnovatyi-Kogan & Lovelace (1997).

Eliot Quataert

1997-10-13T23:59:59.000Z

450

Prairie Winds Wind Farm | Open Energy Information  

Open Energy Info (EERE)

Prairie Winds Wind Farm Prairie Winds Wind Farm Facility Prairie Winds Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Basin Electric Power Coop/Central Power Electric Coop Developer Basin Electric Power Coop/Central Power Electric Coop Energy Purchaser Basin Electric Power Coop/Central Power Electric Coop Location Near Minot ND Coordinates 48.022927°, -101.291435° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":48.022927,"lon":-101.291435,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

451

Wind energy | Open Energy Information  

Open Energy Info (EERE)

(Redirected from Wind) (Redirected from Wind) Jump to: navigation, search Wind energy is a form of solar energy.[1] Wind energy (or wind power) describes the process by which wind is used to generate electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. A generator can convert mechanical power into electricity[2]. Mechanical power can also be utilized directly for specific tasks such as pumping water. The US DOE developed a short wind power animation that provides an overview of how a wind turbine works and describes the wind resources in the United States. Contents 1 Wind Energy Basics 1.1 Equation for Wind Power 2 DOE Wind Programs and Information 3 Worldwide Installed Capacity 3.1 United States Installed Capacity 4 Wind Farm Development 4.1 Land Requirements

452

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

453

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

454

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

455

Energy in the Wind  

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

Provi and BP Energy in the Wind - Exploring Basic Electrical Concepts by Modeling Wind Turbines Curriculum: Wind Power (simple machines, aerodynamics, weather/climatology, leverage, mechanics, atmospheric pressure, and energy resources/transformations) Grade Level: High School Small groups: 2 students Time: Introductory packet will take 2-3 periods. Scientific investigation will take 2-3 periods. (45-50 minute periods) Summary: Students explore basic electrical concepts. Students are introduced to electrical concepts by using a hand held generator utilizing a multimeter, modeling, and designing a wind turbine in a wind tunnel (modifications are given if a wind tunnel is not available). Students investigate how wind nergy is used as a renewable energy resource. e

456

NREL: Wind Research - Publications  

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

Publications Publications The NREL wind research program develops publications about its R&D activities in wind energy technologies. Below you'll find links to recently published publications, links to the NREL Avian Literature and Publications Databases, and information about the Technical Library at the National Wind Technology Center (NWTC). The NWTC's quarterly newsletter, @NWTC, contains articles on current wind energy research projects and highlights the latest reports, papers, articles, and events published or sponsored by NREL. Subscribe to @NWTC. Selected Publications Featured Publication Large-scale Offshore Wind Power in the United States: Assessment of Opportunities and Barriers Here are some selected NWTC publications: 2011 Cost of Wind Energy Review Built-Environment Wind Turbine Roadmap

457

Offshore wind metadata management  

Science Journals Connector (OSTI)

Offshore wind energy is gaining more and more attention from industry and research community due to its high potential in producing green energy and lowering price on electricity consumption. However, offshore wind is facing many challenges, and hence it is still expensive to install in large scale. It therefore needs to be considered from different aspects of technologies in order to overcome these challenges. One of the problems of the offshore wind is that information comes from different sources with diversity in types and format. Besides, there are existing wind databases that should be utilised in order to enrich the knowledge base of the wind domain. This paper describes an approach to managing offshore wind metadata effectively using semantic technologies. An offshore wind ontology has been developed. The semantic gap between the developed ontology and the relational database is investigated. A prototype system has been developed to demonstrate the use of the ontology.

Trinh Hoang Nguyen; Rocky Dunlap; Leo Mark; Andreas Prinz; Bjørn Mo �stgren; Trond Friisø

2014-01-01T23:59:59.000Z

458

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

459

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

460

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

E-Print Network [OSTI]

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

Rhode Island, 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.


461

Sea Surface Roughness and Drag Coefficient as Functions of Neutral Wind Speed  

Science Journals Connector (OSTI)

Near the surface, it is commonly believed that the behavior of the (turbulent) atmospheric flow can be well described by a constant stress layer. In the case of a neutrally stratified surface layer, this leads to the well-known logarithmic wind ...

Hans Hersbach

2011-01-01T23:59:59.000Z

462

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

SciTech Connect (OSTI)

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

Kelley, N.D.

1995-01-01T23:59:59.000Z

463

wind direction | OpenEI  

Open Energy Info (EERE)

direction direction Dataset Summary Description Freedom Field is a not-for-profit organization formed to facilitate development and commercialization of renewable energy solutions. The organization has installed a variety of renewable energy generating technologies at their facility (located at Rock River Water Reclamation in Rockford, IL), with the intention of serving as a demonstration facility. The facility monitors data (at 5-minute intervals) from a weather station, 12.4 kW of PV panels (56 220-watt panels), a 10kW wind turbine (HAWT), a 1.2 kW wind turbine (VAWT), an absorption cooling system, and biogas burners. Source Freedom Field Date Released July 19th, 2011 (3 years ago) Date Updated Unknown Keywords biogas monitoring data PV radiance solar temperature

464

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

465

New England Wind Forum: Buying Wind Power  

Wind Powering America (EERE)

Buying Wind Power Buying Wind Power On this page find information about: Green Marketing Renewable Energy Certificates Green Pricing Green Marketing Green power marketing refers to selling green power in the competitive marketplace, in which multiple suppliers and service offerings exist. In states that have established retail competition, customers may be able to purchase green power from a competitive supplier. Connecticut Connecticut Clean Energy Options Beginning in April 2005, Connecticut's two investor-owned utilities, Connecticut Light and Power and United Illuminating, began to offer a simple, affordable program to their customers for purchasing clean energy such as wind power. In late 2006, stakeholders started to explore a new offering that would convey the price stability of wind energy (and other renewable energy resources) to Connecticut consumers. This new offering is still under development.

466

The role of the Kubo number in two-component turbulence  

SciTech Connect (OSTI)

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

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

2013-09-15T23:59:59.000Z

467

DOE Science Showcase - Wind Power  

Office of Scientific and Technical Information (OSTI)

DOE Science Showcase - Wind Power DOE Science Showcase - Wind Power Wind Powering America Wind Powering America is a nationwide initiative of the U.S. Department of Energy's Wind Program designed to educate, engage, and enable critical stakeholders to make informed decisions about how wind energy contributes to the U.S. electricity supply. Wind Power Research Results in DOE Databases IEA Wind Task 26: The Past and Future Cost of Wind Energy, Work Package 2, Energy Citations Database NREL Triples Previous Estimates of U.S. Wind Power Potential, Energy Citations Database Dynamic Models for Wind Turbines and Wind Power Plants, DOE Information Bridge 2012 ARPA-E Energy Innovation Summit: Profiling General Compression: A River of Wind, ScienceCinema, multimedia Solar and Wind Energy Resource Assessment (SWERA) Data from the

468

Numerical simulation and wind tunnel studies of pollution dispersion in an isolated street canyon  

Science Journals Connector (OSTI)

A three dimensional numerical modelling study of an urban isolated street canyon are done using Computational Fluid Dynamics (CFD) software FLUENT. The concentration predictions of FLUENT are compared with the Environmental Wind Tunnel (EWT) test results conducted at Indian Institute of Technology, Delhi for the Aspect Ratio (AR) of 1 and 1.5 at perpendicular wind direction. In FLUENT, three different kâ??? turbulence models, i.e., standard, Renormalisation Group (RNG) and realisable, are used. RNG model has been found to be best matched with the wind tunnel results (d = 0.80) for AR = 1, showing that for separated flows, it works best.

Seema Awasthi; K.K. Chaudhry

2009-01-01T23:59:59.000Z

469

New England Wind Forum: Selling Wind Power  

Wind Powering America (EERE)

Selling Wind Power Selling Wind Power Markets are either well-developed or developing for each of the 'products' produced by wind generators. These include electricity products and generation attributes. Electricity Electricity can be used in two ways: on-site (interconnected behind a retail customer's meter) of for sales of electricity over the electric grid. On-site generation can displace a portion of a customer's purchases of electricity from the grid. In addition, net metering rules are in place at the state level that in some cases allow generation in excess of on-site load to be sold back to the local utility (see state pages for net metering specifics). For sales over the electricity grid, the Independent System Operator of New England (ISO New England) creates and manages a wholesale market for electric energy, capacity, and ancillary services within the New England Power Pool (NEPOOL). Wind generators may sell their electric energy and capacity in spot markets organized by the ISO, or they may contract with wholesale buyers to sell these products for any term to buyers operating in the ISO New England marketplace. Wind generators do not generally produce other marketable ancillary services. The ISO has rules specific to the operation of wind generators reflecting operations, scheduling, calculation of installed capacity credit, and so forth.

470

Accepted, Nuclear Fusion, 1999 Turbulent Transport and Turbulence in Radiative I-Mode Plasmas in  

E-Print Network [OSTI]

Accepted, Nuclear Fusion, 1999 Turbulent Transport and Turbulence in Radiative I-Mode Plasmas of Physics University of Alberta Edmonton, Alberta Canada, T6G 2J1 1/4/00 17:25 PM #12;Accepted, Nuclear Fusion, 1999 1 Abstract First measurements of turbulence levels and turbulence-induced transport

California at San Diego, University of

471

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

472

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

473

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; Güdel, M; Eggl, S

2015-01-01T23:59:59.000Z

474

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

475

Usage of turbulence for superresolved imaging  

Science Journals Connector (OSTI)

We have used the turbulent flow of hot air to improve the diffraction limits of resolution in an imaging system. A time-multiplexing approach was applied and used the turbulent flow...

Zalevsky, Zeev; Rozental, Shay; Meller, Moshe

2007-01-01T23:59:59.000Z

476

Flight–crash events in turbulence  

Science Journals Connector (OSTI)

...Institute of Science, Rehovot 76100...Mechanical and Aerospace Engineering, Cornell...14). The recent advances in our ability...turbulent flow . Science 311 ( 5762 ): 835...turbulence: recent results...Cooperation in Science and Technology...

Haitao Xu; Alain Pumir; Gregory Falkovich; Eberhard Bodenschatz; Michael Shats; Hua Xia; Nicolas Francois; Guido Boffetta

2014-01-01T23:59:59.000Z

477

Holographic Vortex Liquids and Superfluid Turbulence  

Science Journals Connector (OSTI)

...of Kelvin waves flowing along vortex strings in 3D quantum turbulence...theory correlators from non-critical string theory . Phys. Lett. B...S. , Emergence of turbulence in an oscillating Bose-Einstein condensate . Phys. Rev...

Paul M. Chesler; Hong Liu; Allan Adams

2013-07-26T23:59:59.000Z

478

Two-fluid turbulence including electron inertia  

E-Print Network [OSTI]

We present a full two-fluid magnetohydrodynamic (MHD) description for a completely ionized hydrogen plasma, retaining the effects of the Hall current, electron pressure and electron inertia. According to this description, each plasma species introduces a new spatial scale: the ion inertial length $\\lambda_{i}$ and the electron inertial length $\\lambda_{e}$, which are not present in the traditional MHD description. In the present paper, we seek for possible changes in the energy power spectrum in fully developed turbulent regimes, using numerical simulations of the two-fluid equations in two-and-a-half dimensions (2.5D). We have been able to reproduce different scaling laws in different spectral ranges, as it has been observed in the solar wind for the magnetic energy spectrum. At the smallest wavenumbers where plain MHD is valid, we obtain an inertial range following a Kolmogorov $k^{-5/3}$ law. For intermediate wavenumbers such that $\\lambda_{i}^{-1} \\lambda_{e}^{-1}$ arises. The power spectrum for magnetic...

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

2014-01-01T23:59:59.000Z

479

Spatial Structure and Field-Line Diffusion in Transverse Magnetic Turbulence  

Science Journals Connector (OSTI)

We examine magnetic surfaces and randomization of field lines with fluctuations transverse to a uniform magnetic field. Analogy with passive scalar transport in inviscid 2D flow provides realizations of magnetic surfaces and motivates a nonperturbative statistical approach. The stochastic wandering of magnetic field lines leads to diffusive perpendicular transport. For two-component fluctuations, appropriate for solar wind turbulence, the diffusion coefficient is a nonadditive combination of slab and 2D coefficients, approaching the latter in the small amplitude limit.

W. H. Matthaeus; P. C. Gray; D. H. Pontius; Jr.; J. W. Bieber

1995-09-11T23:59:59.000Z

480

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

Note: This page contains sample records for the topic "temperature turbulence wind" from the National Library of EnergyBeta (NLEBeta).
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481

NREL: Wind Research - News  

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

Below are some select news stories from the National Wind Technology Below are some select news stories from the National Wind Technology Center. Subscribe to the RSS feed RSS . Learn about RSS. January 3, 2014 New Modularization Framework Transforms FAST Wind Turbine Modeling Tool The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) recently released an expanded version of its FAST wind turbine computer-aided engineering tool under a new modularization framework. January 2, 2014 The Denver Post Highlights the NWTC's New 5-MW Dynamometer On January 2, a reporter from The Denver Post toured the new 5-megawatt dynamometer test facility at the National Wind Technology Center (NWTC). Archives 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 Printable Version Wind Research Home Capabilities Projects Facilities

482

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

483

Session: Offshore wind  

SciTech Connect (OSTI)

This session at the Wind Energy and Birds/Bats workshop consisted of two presentations. Due to time constraints, a discussion period was not possible. The session addressed the current state of offshore wind energy development. The first presentation ''Monitoring Program and Results: Horns Rev and Nysted'' by Jette Gaarde summarized selected environmental studies conducted to date at operating offshore wind turbine projects in Denmark and lessons from other offshore wind developments in Europe. Wildlife impacts studies from the Danish sites focused on birds, fish, and mammals. The second presentation ''What has the U.S. Wind Industry Learned from the European Example'' by Bonnie Ram provided an update on current permit applications for offshore wind developments in the U.S. as well as lessons that may be drawn from the European experience.

Gaarde, Jette; Ram, Bonnie

2004-09-01T23:59:59.000Z

484

turbulent heat International Journal of Numerical  

E-Print Network [OSTI]

Enhanced turbulent heat transfer 47 International Journal of Numerical Methods for Heat & Fluid, Hsinchu,Taiwan Keywords Heat transfer, Fluids, Flow, Turbulence, Numerical methods Abstract This study evaluates low Reynolds number models of turbulence for numerical computations on the heat transfer and fluid

Lin, Wen-Wei

485

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

486

Protostellar Outflow Evolution in Turbulent Environments  

SciTech Connect (OSTI)

The link between turbulence in star formatting environments and protostellar jets remains controversial. To explore issues of turbulence and fossil cavities driven by young stellar outflows we present a series of numerical simulations tracking the evolution of transient protostellar jets driven into a turbulent medium. Our simulations show both the effect of turbulence on outflow structures and, conversely, the effect of outflows on the ambient turbulence. We demonstrate how turbulence will lead to strong modifications in jet morphology. More importantly, we demonstrate that individual transient outflows have the capacity to re-energize decaying turbulence. Our simulations support a scenario in which the directed energy/momentum associated with cavities is randomized as the cavities are disrupted by dynamical instabilities seeded by the ambient turbulence. Consideration of the energy power spectra of the simulations reveals that the disruption of the cavities powers an energy cascade consistent with Burgers-type turbulence and produces a driving scale-length associated with the cavity propagation length. We conclude that fossil cavities interacting either with a turbulent medium or with other cavities have the capacity to sustain or create turbulent flows in star forming environments. In the last section we contrast our work and its conclusions with previous studies which claim that jets can not be the source of turbulence.

Cunningham, A; Frank, A; Carroll, J; Blackman, E; Quillen, A

2008-04-11T23:59:59.000Z

487

Wind Turbine Blade Design  

K-12 Energy Lesson Plans and Activities Web site (EERE)

Blade engineering and design is one of the most complicated and important aspects of modern wind turbine technology. Engineers strive to design blades that extract as much energy from the wind as possible throughout a range of wind speeds and gusts, yet are still durable, quiet and cheap. A variety of ideas for building turbines and teacher handouts are included in this document and at the Web site.

488

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]

by wind profilers at the Wharton (WH), Liberty (LB), Houston Southwest (HSW), Ellington (EL), and LaMarque (LM) sites.................................................................. 93 18 Skew-T of WH radiosonde data at 1100 UTC...), Houston Southwest (HSW), Ellington (EL), and LaMarque (LM) sites ....................................... 97 21 The ML height distribution at 1600 UTC around the city of Houston...

Smith, Christina Lynn

2005-08-29T23:59:59.000Z

489

Howden Wind Turbines Ltd | Open Energy Information  

Open Energy Info (EERE)

Howden Wind Turbines Ltd Jump to: navigation, search Name: Howden Wind Turbines Ltd Place: United Kingdom Sector: Wind energy Product: Howden was a manufacturer of wind turbines in...

490

ABO Wind AG | Open Energy Information  

Open Energy Info (EERE)

AG Place: Hessen, Germany Zip: 65193 Sector: Bioenergy, Wind energy Product: German developer of wind and bioenergy generation assets. ABO Wind has no direct holding in any wind...

491

TS Wind Power Developers | Open Energy Information  

Open Energy Info (EERE)

TS Wind Power Developers Jump to: navigation, search Name: TS Wind Power Developers Place: Satara, Maharashtra, India Sector: Wind energy Product: Setting up 30MW wind farm in...

492

Daqing Longjiang Wind Power | Open Energy Information  

Open Energy Info (EERE)

Longjiang Wind Power Jump to: navigation, search Name: Daqing Longjiang Wind Power Place: Daqing, Heilongjiang Province, China Zip: 163316 Sector: Wind energy Product: Local wind...

493

Heilongjiang Lishu Wind Power | Open Energy Information  

Open Energy Info (EERE)

Lishu Wind Power Jump to: navigation, search Name: Heilongjiang Lishu Wind Power Place: Heilongjiang Province, China Sector: Wind energy Product: China-based wind project developer...

494

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...

495

Blyth Offshore Wind Ltd | Open Energy Information  

Open Energy Info (EERE)

Blyth Offshore Wind Ltd Jump to: navigation, search Name: Blyth Offshore Wind Ltd Place: United Kingdom Sector: Renewable Energy, Wind energy Product: Blyth Offshore Wind Limited,...

496

2013 Wind Technologies Market Report Presentation | Department...  

Office of Environmental Management (EM)

3 Wind Technologies Market Report Presentation 2013 Wind Technologies Market Report Presentation Presentation summarizing the 2013 Wind Technologies Market Report. 2013 Wind...

497

Environmental Wind Projects | Department of Energy  

Energy Savers [EERE]

Wind Projects Environmental Wind Projects This report covers the Wind and Water Power Technologies Office's environmental wind projects from fiscal years 2006 to 2014....

498

NREL: Wind Research - Research and Development  

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

Printable Version Wind Research Home Research & Development Utility-Scale Wind Turbines Offshore Wind Turbines Small Wind Turbines Grid Integration Market Acceleration...

499

Workforce Development Wind Projects | Department of Energy  

Energy Savers [EERE]

Workforce Development Wind Projects Workforce Development Wind Projects This report covers the Wind and Water Power Technologies Office's workforce development wind projects from...

500

Environmental Wind Projects | Department of Energy  

Energy Savers [EERE]

Environmental Wind Projects Environmental Wind Projects This report covers the Wind and Water Power Technologies Office's environmental wind projects from fiscal years 2006 to...