... prediction models. Wind speed is one of the environmental variables controlling CWA volatilization. therefore. an accurate ...
DTIC Science & Technology
Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whe...
National Technical Information Service (NTIS)
The turbulence encountered by a point on a rotating wind turbine blade has characteristics that in some important respects are different from those measured by a stationary anemometer. The conventional one-peaked continuous spectrum becomes, broadly, a tw...
. Improving the accuracy of the wind speed data will improve weather prediction and contribute to a better tanker geometry. 3. SUMMARY For accurate weather prediction and for better prediction of future changes
E-print Network
Wind tunnel and field experiments have shown that the fast-response three-component sonic anemometer is a highly accurate wind speed sensor. When sonic anemometers were used as reference sensors for wind speed, slower response cup anemometers were found t...
shown to be accurate for wind speed of up to at least 20 m/s. The global wind fields from QuikSCAT have been routinely assimilated into the numerical weather ...
NASA Website
... design power limit was exceeded during these trials because the accurate setting of the thyristor control ... Each table contains the true wind speed ...
In this study, we investigate the accuracy of measure-correlate-predict (MCP) algorithms and log law/power law scaling using data from two tall towers in coastal environments. We find that MCP algorithms accurately predict sea breeze winds and that log law/power law scaling methods struggle to predict 50-meter wind ...
NASA Astrophysics Data System (ADS)
knowledge of wind turbine behaviour in the atmosphere and assessment of power performance of wind turbines measurement in wind energy. It is being applied in high numbers around the world for wind energy assessments in high numbers around the world for wind energy assessments. It is also ...
Winds are an important climatic variable in utility operational planning. Light winds reduce air quality, severe winds represent a threat to structures, and dispatchers must know the wind speed if wind energy conversion facility output is to be anticipated. This report ...
Energy Citations Database
A variety of instruments and techniques are used to study and measure the gases in volcanic plumes. Regardless of the approach an accurate measure of plume velocity must be made. Wind measurements made near the elevation of the plume are considerably more...
Accurate short-term wind speed forecasts for utility-scale large wind farms will be crucial for the U.S. Department of Energy's goal of providing 20% of total electricity from wind by 2030. Communicating the level of uncertainty in these wind speed ...
threshold wind friction speed freestream wind speed wind speed particle speed relative speed between particle and wind initial particle upward velocity ...
Site matching of wind turbine generators is investigated based on appropriate selection of statistical models and means of wind speed data. The wind speed means are computed using arithmetic mean, root mean square and cubic mean cuberoot. Wind Speed ...
CHARACTERIZATION OF THE FLOW FIELD AND WIND SPEED PROFILES IN MICROBALANCE WIND TUNNELS FOR MEASUREMENT OF ...
... Title : A LOW SPEED WIND TUNNEL FOR MEASURING THE EFFECT OF WIND ON BUOYANT DIFFUSION FLAMES. ...
The higher wind speeds of the offshore environment make it an attractive setting for future wind farms. With sparser field measurements, the theoretical probability distribution of short-term wind speeds becomes more important in estimating values such as average power output and fatigue load. ...
average wind speed and wind power density by season and annually. Wind speed frequencies, covariances of wind speed and direction, and wind power ...
The United States Department of Agriculture¿s high-speed wind tunnel facility in College Station, Texas, USA was used to determine droplet size distributions generated by dispersant delivery nozzles at wind speeds comparable to those used in aerial dispersant application. A laser particle size anal...
Technology Transfer Automated Retrieval System (TEKTRAN)
BMT ARGOSS operates the WRF atmosphere model for regional weather forecasts and long-term historical analyses across the globe. Operational forecasts for the Netherlands are provided to an energy company to obtain power output forecasts up to 5 days ahead. The WRF model is operated at resolutions of 3 km and 9 km. Forecasts are provided 4 times per day, up to 120 hours into the future. To ...
Small wind turbines often use some form of furling (yawing and/or tilting out of the wind) to protect against excessive power generation and rotor speeds in high winds.The verification study demonstrated the correct implementation of FAST's furling dynamics. During validation, the model tends to predict ...
The use of land based wind data in nearshore oceanographic work is common, but these winds do not accurately reflect coastal oceanic winds. Ocean winds are often underestimated by a factor of 2 and directional differences are also observed. Wind time series from land and ...
A previous altimeter wind speed retrieval algorithm was developed on the basis of wind speeds in the
NASA Technical Reports Server (NTRS)
The Department of Energy (DOE) Environment, Safety and Health Compliance Assessment (Tiger Team) of the Savannah River Site (SRS) questioned the method by which wind speed sensors (cup anemometers) are calibrated by the Environmental Technology Section (ETS). The Tiger Team member was concerned that calibration data was generated by running the ...
DOE Information Bridge
The increased integration of wind power into the electric grid, as nowadays occurs in Portugal, poses new challenges due to its intermittency and volatility. Wind power prediction plays a key role in tackling these challenges. The contribution of this paper is to propose a new approach, combining fuzzy clustering and PCA, that uses historical data and ...
To properly evaluate the wind power potential of a site, an accurate and complete data set of preferably several years length are needed. Hourly wind speed and direction data are also preferred so a detailed analysis can be done of the important wind char...
... TR-0313 OSD - 1366 SURFACE WIND SPEED DISTRIBUTIONS June 1992 DTIC ... 0 0 0 0 0 WIND SPEED (MPS) Cm__ 0 WIND SPEED (MPS) ...
As ever more offshore sites are being investigated for the installation of wind farms, there is a need for accurate estimates of the long-term mean wind speeds at these sites. The cost of installing masts at offshore sites is high compared with onshore sites. In the short term this cost may be difficult to avoid. ...
The use of sodars for wind shear detection is studied. Sodars have been employed to the measure wind shear during heavy rain; Doppler sodar measurements are compared to aircraft measurements, and good agreement is observed. The advantages of sodar wind shear detection systems are discussed. The design of a megasodar which will be able ...
In 1999 Hurricane Gert passed over an autonomous hydrophone in the North Atlantic yielding a clear recording of the underwater noise generated by the hurricane. By correlating the noise with meteorological data from reconnaissance aircraft and satellites, it is shown that underwater noise intensity in the 10-50-Hz band is proportional to local wind speed ...
The ability of the WRF atmospheric model to forecast wind speed over the Nysted wind park was investigated as a function of time. It was found that in the time period we considered (August 1-19, 2008), the model is able to predict wind speeds reasonably accurately for 48 ...
The WaveWatch III model over-predicts wave heights at high winds speeds. One potential reason is that the momentum flux to the waves is overestimated within the model. Recent results indicate that the momentum flux at wind speeds above 30-40 m s-1 plateaus [Powell et al., 2003] and may lead to a reduction in the ...
Measured and predicted rotor performance for the SERI advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. ...
Measured and predicted rotor performance for the Solar Energy Research Institute (SERI) advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit ...
Incoherent Doppler wind lidar measures the wind by detecting the frequency shift of the laser backscattering from aerosol and atmosphere molecules. The wind measurement sensitivity of edge detection technology like iodine vapor filter depends on the aerosol load of probe volume. The current Direct detect wind lidar ...
... systems are sensitive to winds in the ... The observed wind speed distributions were adequately ... Weibull, Gamma, Log-normal, Upper air, Wind speed. ...
... versus QuikScat wind speeds are shown in Figure 5. In general, the WindSat wind speeds are higher than the QuikScat winds at wind speeds over ...
wind speed records with average delays from several reference ... averages wind speed records at all prediction sites in a wind ...
... Title : Characterization of the Flow Field, Wind Speed Profiles and Turbulence Intensity in Environmental Wind Tunnels for Measurement of Agent ...
Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whether one year of wind data is representative of long-term ...
... Keywords: Local winds; Wind effects; Wind direction; Wind speed; Turbulence; Antitriptic winds; Katabatic and Anabatic winds; Pressure gradient ...
This is a study to quantify U.S. wind power at 80 m (the hub height of large wind turbines) and to investigate whether winds from a network of farms can provide a steady and reliable source of electric power. Data from 1327 surface stations and 87 soundings in the United States for the year 2000 were used. Several methods were tested ...
A computer model of a horizontal axis wind turbine (HOOT) with four structural degrees of freedom has been derived and verified. The four degrees of freedom include flapwise motion of the blades, teeter motion, and variable rotor speed. Options for the variable rotor speed include synchronous, induction, and constant-tip ...
Numerical modeling and simulation of the NREL Phase VI Rotor operation was attempted using a commercial CFD code (ANSYS FLUENT� v12.1). The extensive experimental data that was collected at the NASA Ames Research Center 80'�120' Wind Tunnel allowed a detailed evaluation of the numerical result, in order to asses the accuracy of the numerical modeling approach. Computations ...
The accurate modeling of wind turbines is an extremely challenging problem due to the tremendous complexity of the machines and the turbulent and unpredictable conditions in which they operate. Adaptive control techniques are well suited to nonlinear applications, such as wind turbines, which are difficult to ...
The use of a piloted aircraft to determine the magnitude and direction of the wind speed vector involves the direct measurement and recording of several basic parameters, such as ground speed, drift angle and air speed from which the wind speed vector is ...
Wind, driving oceans, and the links between them to the atmospheres compose a critical parameter for the world circulation model as well as for the evaluation of climate changes. Traditionally, wind velocities have been reported by ships of opportunity and recorded on a network of buoys; they have also recently been generated by numerical weather ...
We have analyzed hourly observations of overlake wind speed obtained from the eight National Data Buoy Center buoys deployed in the Great Lakes to determine the long-term (10 to 12 year) statistical characteristics of wind events over the lakes. We find that a generalized double-exponential model accurately ...
Depolarized (de-pol) radar backscatter is now produced by many spaceborne satellites. Analysis of RADARSAT-2 (R2) quad-polarization (quad-pol) data with collocated in situ ocean wind measurements reveals that the de-pol radar backscatter does not saturate in high winds. This is a significant development for radar wind sensing, because ...
The energy sector comprises approximately two-thirds of global total greenhouse gas emissions. For this and other reasons, renewable energy resources including wind power are being increasingly harnessed to provide electricity generation potential with negligible emissions of carbon dioxide. The wind energy resource is naturally a function of the climate ...
PubMed
... indicate that for a complete analysis both wind speed and shear should be considered. For example, a profile with strong winds throughout several ...
Two methods are proposed to assess the impact of multiple wind farms on a large electrical power system. The methods are based on the Monte Carlo simulation of the wind speed occurring in each wind farm, taking into account measurements of mean values and correlations. The first method is based on the ...
The El Nino Southern Oscillation (ENSO) is a well-known source of inter-annual climate variability for both precipitation and temperature in the northern Great Plains. The northern Great Plains also have the largest wind resource in the United States. With the continued growth of wind energy, ENSO's effect on wind ...
Page 1. Practical Wind Speed and Rain ... Equations for estimating wind speed and rain rate from underwater noise are derived in this paper. ...
At present several satellites for earth gravity field measurement are in low polar orbits. These satellites have slender shapes and are equipped with highly sensitive accelerometer packages. Accelerometer data of these satellites can be used to determine local atmospheric density and winds. For this task accurate aerodynamic data of the satellites are ...
This study has demonstrated that high-resolution scatterometer measurements in tropical cyclones and other high-marine surface wind regimes may be retrieved accurately for wind speeds up to about 35 mls (1-hour average at 10 m) when the scatterometer data...
The presence of tall buildings has in many cases created uncomfortable and dangerous wind conditions at pedestrian level. Here a successful simple methodology was established to evaluate pedestrian level winds in a built-up urban terrain. Experiments were conducted using a 1:300 geometric scale model of the University of Minnesota hospital complex (UOMHC) ...
Numerical weather prediction models generally use the traditional bulk relation for wind stress, which is characterized by a drag coefficient. Computation of the drag coefficient is usually based on the Charnock relation, which has been proven to be an accurate formulation for many meteorological as well as oceanographic applications. According to the ...
The sudden and widespread wind technological developments of the last decade raised the question of the effectiveness of wind energy utilisation in moderate wind regions, such as Hungary. In order to support governmental efforts and to facilitate initiatives on renewable energy consumption a research project has started on mapping ...
This report proves that the characteristics of turbulence that are experienced by a rotating wind turbine rotor blade are in principle and in practice very different than those experienced by a nonrotating rotor blade. Thus conventional wind characteristics, which are formulated for the nonrotating frame of reference, are more inaccurate than generally ...
High-quality short-term forecasts of wind speed are vital to making wind power a more reliable energy source. Gneiting et al. (2006) have introduced a model for the average wind speed two hours ahead based on both spatial and temporal information. The forecasts produced by this model are ...
In this activity, students explore the effect of the combination of temperature and wind speed on human comfort. Then they use a formula to compute the Fahrenheit wind chill for a specific wind speed on a specific temperature.
NSDL National Science Digital Library
... Accession Number : AD0620221. Title : WIND-SPEED AND WIND-DIRECTION DISTRIBUTIONS AT ARGUS ISLAND OFF BERMUDA. ...
Probability of wind is calculated by wind speed and direction observations taked from a wind-vane with both light and heavy boards and given by 8-point ...
determine wind speed (use Beaufort's scale for wind speed) and wind vane and compass for wind direction.* ( *See below for more details.) ...
Cosmic Ray Associated Atmospheric Pressure and Wind Speed Records, Antarctica [ Cosmic_Ray_PW] Records of atmospheric pressure and wind speed used in ...
A new method is described for computing free surface flows. The method allows for arbitrary wind profiles to be imposed above the surface as well as arbitrary subsurface current and density profiles. The method combines recent advances in projection methods for stratified flows with level set strategies for computing the motion of a distinguished interface. High resolution ...
... Title : Development of a Highly Efficient and Accurate Wind-Wave Simulation Framework for Operational Data Assimilation. ...
