Wind Kinetic Energy Research Articles

Long-Term Variability of the Wind Field over the Indian Ocean Based on ERA-Interim Reanalysis

A detailed study of long-term variability of winds using 30 years of data from the European Centre for Medium-range Weather Forecasts global reanalysis (ERA-Interim) over the Indian Ocean has been carried out by partitioning the Indian Ocean into six zones based on local wind extrema. The trend of mean annual wind speed averaged over each zone shows a significant increase in the equatorial region, the Southern Ocean, and the southern part of the trade winds. This indicates that the Southern Ocean winds and the southeast trade winds are becoming stronger. However, the trend for the Bay of Bengal is negative, which might be caused by a weakening of the monsoon winds and northeast trade winds. Maximum interannual variability occurs in the Arabian Sea due to monsoon activity; a minimum is observed in the subtropical region because of the divergence of winds. Wind speed variations in all zones are weakly correlated with the Dipole Mode Index (DMI). However, the equatorial Indian Ocean, the southern part of the trade winds, and subtropical zones show a relatively strong positive correlation with the Southern Oscillation Index (SOI), indicating that the SOI has a zonal influence on wind speed in the Indian Ocean. Monsoon winds have a decreasing trend in the northern Indian Ocean, indicating monsoon weakening, and an increasing trend in the equatorial region because of enhancement of the westerlies. The negative trend observed during the non-monsoon period could be a result of weakening of the northeast trade winds over the past few decades. The mean flux of kinetic energy of wind (FKEW) reaches a minimum of about 100 W m−2 in the equatorial region and a maximum of about 1500 W m−2 in the Southern Ocean. The seasonal variability of FKEW is large, about 1600 W m−2, along the coast of Somalia in the northern Indian Ocean. The maximum monthly variability of the FKEW field averaged over each zone occurs during boreal summer. During the onset and withdrawal of monsoon, FKEW is as low as 50 W m−2. The Southern Ocean has a large variation of about 1280 W m−2 because of strong westerlies throughout the year.

PERFORMANCE OF WIND TURBINE VENTILATOR AS ELECTRICITY GENERATOR IN BOAT FISHING

The specific objective of the research activities is to produce a package of wind power technology in the fishing boat without fuel, strengthen energy independence for fishermen, achievement data performance wind power plant in a fishing boat. The method used is to testing wind turbine ventilator as power plants in the fishing boat. Wind turbine ventilator, wind energy capture from multiple directions. This wind turbine receives wind energy then converts the kinetic energy of wind into mechanical energy for rotating electrical generator. This electrical energy is stored in batteries to stabilize the flow of electricity from the battery and then used as a source of energy for lighting fishing boat.

Trading Energy Yield for Frequency Regulation: Optimal Control of Kinetic Energy in Wind Farms

The burden on conventional units to regulate the system frequency increases if they are replaced due to wind farms. This paper explores up to which time scales the rotating kinetic energy in wind turbines can smooth frequency variations and assist with the regulation task. To this end, a comparison is made between a standard wind turbine controller and optimal control of wind turbines, respectively derived from causal time-domain simulations and an optimization algorithm that allows predicting. The latter algorithm is used to give a benchmark for the smoothing potential, shown by plotting the Pareto efficiency of the normalized standard deviation of frequency variability versus a normalized measure of the energy yield. Results indicate that smoothing comes with an energy loss that is determined by the energy content of power imbalances. It is shown that a wind share of 20%, within the instantaneous generation mix, can absorb frequency variations on timescales up to 100 sec while the energy loss is limited to only 2%. A higher share of wind power aggravates frequency variability. Nevertheless, in such circumstances the potential of rotating kinetic energy in wind farms increases.

Numerical Simulation for the Aerodynamics of Vertical Axis Wind Turbine with Two Different Rotors Having Movable Vanes

Wind energy has seen a rapid growth worldwide. Wind turbines are typical devices that convert the kinetic energy of wind into electricity. Researches in the past have proved that Vertical Axis Wind Turbines (VAWTs) are more suitable for urban areas than Horizontal Axis Wind Turbines (HAWTs). In the present design of the VAWT, the power prodused depends on the drag force generated by the individual blades and interactions between them in a rotating configuration. Numerical simulation for the aerodynamics of VAWT with tow different rotors (Three and Foure blades ) having movable vanes are curred out. The For numerical simulation, commercially available computational fluid dynamic (CFD) softwares GAMBIT and FLUENT are used. In this work the Shear Stress Transport (SST) k-ω turbulence model was used which is better than the other turbulence models available as suggested by some researchers. The predicted results show agreement with those reported in the literature for VAWT having different blades designs.

A 32-year perspective on the origin of wind energy in a warming climate

Based on assimilated meteorological data for the period January 1979 to December 2010, the origin of wind energy is investigated from both mechanical and thermodynamic perspectives, with special focus on the spatial distribution of sources, historical long-term variations and the efficiency for kinetic energy production. The dry air component of the atmosphere acts as a thermal engine, absorbing heat at higher temperatures, approximately 256 K, releasing heat at lower temperatures, approximately 252 K. The process is responsible for production of wind kinetic energy at a rate of 2.46 W/m2 sustaining thus the circulation of the atmosphere against frictional dissipation. The results indicate an upward trend in kinetic energy production over the past 32 years, indicating that wind energy resources may be varying in the current warming climate. This analysis provides an analytical framework that can be adopted for future studies addressing the ultimate wind energy potential and the possible perturbations to the atmospheric circulation that could arise as a result of significant exploitation of wind energy.

Energetics characteristics of the super magnetic storm on November 20, 2003 based on 3D global MHD simulation

The three-dimensional global magnetohydrodynamic model (PPM-LR MHD) is employed to investigate the energy budget in the solar wind-magnetosphere system during the super magnetic storm on November 20, 2003, one of the biggest storms during the last decade with Dst ∼ −500 nT. During this event, about 23% solar wind kinetic energy is transferred into the magnetosphere. The total energy input is estimated to be about 9.50×1017 J, about 14 times of a moderate storm. The energy dissipation via the inner magnetosphere is less than the energy input with the coupling efficiency of ∼63.3%. The energy dissipated via ring current injection is less than that via high-latitude ionosphere at the initial stage of the super storm. Furthermore, both the simulation results and the empirical results indicate that the ratio of ring current injection to the total energy output increases with the enhancement of the magnetospheric activity level. These are consistent with the statistical results we have got before. The empirical equations underestimate the solar wind kinetic energy, the energy input, and the energy dissipation via high-latitude ionosphere compared with the simulation results; however, the coupling efficiency of the high-latitude ionosphere (23.4%) is close to the simulation result (23.1%) during the entire storm time period.

Solar wind‐magnetosphere energy coupling function fitting: Results from a global MHD simulation

AbstractQuantitatively estimating the energy input from the solar wind into the magnetosphere on a global scale is still an observational challenge. We perform three‐dimensional magnetohydrodynamic (MHD) simulations to derive the energy coupling function. Based on 240 numerical test runs, the energy coupling function is given by. We study the correlations between the energy coupling function and a wide variety of magnetospheric activity, such as the indices ofDst,Kp,ap,AE,AU,AL, the polar cap index, and the hemispheric auroral power. The results indicate that this energy coupling function gives better correlations than theεfunction. This result is also applied to a storm event under northward interplanetary magnetic field conditions. About 13% of the solar wind kinetic energy is transferred into the magnetosphere and about 35% of the input energy is dissipated in the ionosphere, consistent with previous studies.

Eddy kinetic energy study of the snowstorm over Southern China in January 2008

The energetics of the third stage of a snowstorm over China was analyzed using ECWMF data. The analysis of the energy budget for the Middle East trough and the western Pacific trough that developed toward China on 25–28 January 2008 showed the advection of the geopotential by the ageostrophic wind to be both a crucial source and the primary sink of the eddy kinetic energy centers associated with the troughs. The magnitudes of the energy conversion terms, interaction kinetic energy conversion and baroclinic conversion, were too small to explain the development of the energy centers and the jet streaks. The energy centers gained energy at their entrance regions via the convergence of the ageostrophic geopotential fluxes, and then lost energy at their exit regions by the same fluxes. At the entrance regions, the fluxes converged, increasing the geopotential gradient, which generated a stronger geostrophic wind and higher kinetic energy, resulting in an ascending motion in this area. When the troughs moved to China, the ascending motion caused by the convergence of the fluxes at entrance region intensified the snowstorms over central and southern China.

Multi-MW급 풍력발전용 블레이드 설계에 관한 연구 Part I : 공력-구조 설계 및 통합하중해석

A rotor blade is an important device that converts kinetic energy of wind into mechanical energy. Rotor blades affect the power performance, energy conversion efficiency, and loading and dynamic stability of wind turbines. Therefore, considering the characteristics of a wind turbine system is important for achieving optimal blade design. This study examined the general blade design procedure for a wind turbine system and aero-structure design results for a 2-MW class wind turbine blade (KR40.1b). As suggested above, a rotor blade cannot be designed independently, because its ultimate and fatigue loads are highly dependent on system operating conditions. Thus, a reference 2-MW wind turbine system was also developed for the system integrated load calculations. All calculations were performed in accordance with IEC 61400-1 and the KR guidelines for wind turbines.

Solar wind‐magnetosphere energy coupling efficiency and partitioning: HILDCAAs and preceding CIR storms during solar cycle 23

AbstractA quantitative study on the energetics of the solar wind‐magnetosphere‐ionosphere system during High‐Intensity, Long‐Duration, Continuous AE Activity (HILDCAA) events for solar cycle 23 (from 1995 through 2008) is presented. For all HILDCAAs, the average energy transferred to the magnetospheric/ionospheric system was ~6.3 ×1016 J, and the ram kinetic energy of the incident solar wind was ~7.1 ×1018 J. For individual HILDCAA events the coupling efficiency, defined as the ratio of the solar wind energy input to the solar wind kinetic energy, varied between 0.3% and 2.8%, with an average value of ~0.9%. The solar wind coupling efficiency for corotating interaction region (CIR)‐driven storms prior to the HILDCAA events was found to vary from ~1% to 5%, with an average value of ~2%. Both of these values are lower than the> 5% coupling efficiency noted for interplanetary coronal mass ejection (and sheath)‐driven magnetic storms. During HILDCAAs, ~67% of the solar wind energy input went into Joule heating, ~22% into auroral precipitation, and ~11% into the ring current energy. The CIR‐storm Joule heating (~49%) was noticeably less than that during HILDCAAs, while the ring current energies were comparable for the two. Joule dissipation was higher for HILDCAAs that followed CIR‐storms (88%) than for isolated HILDCAAs (~60%). Possible physical interpretations for the statistical results obtained in this paper are discussed.

Bow shock: Power aspects

It is clear that the primary energy source for magnetospheric processes is the solar wind, but the process of energy transfer from the solar wind into the magnetosphere, or rather, to convecting magnetospheric plasma, appears to be rather complicated. Bow shock is a powerful transformer of the solar wind kinetic energy into the gas dynamic and electromagnetic energy. A jump of the magnetic field tangential component at front crossing means that the front carries an electric current. The solar wind kinetic energy partly transforms to gas kinetic and electromagnetic energy during its passage through the bow shock front. The transition layer (magnetosheath) can use part of this energy for accelerating of plasma, but can conversely spend part its kinetic energy on the electric power generation, which afterwards may be used by the magnetosphere. Thereby, transition layer can be both consumer (sink) and generator (source) of electric power depending upon special conditions. The direction of the current behind the bow shock front depends on the sign of the IMF Bz-component. It is this electric current which sets convection of plasma in motion.

On nonlinear cascades and resonances in the outer magnetosphere

The paper addresses nonlinear phenomena that control the interaction between plasma flow (solar wind) and magnetic barrier (magnetosphere). For the first time we demonstrate that the dominant solar wind kinetic energy: (i) excites boundary resonances and their harmonics which modulate plasma jets under the bow shock; (ii) produces discrete three-wave cascades, which could merge into a turbulent-like one; (iii) jet produced cascades provide the effective anomalous plasma transport inside and out of the magnetosphere; (iv) intermittency and multifractality characteristics for the statistic properties of jets result in a super-ballistic turbulent transport regime. Our results could be considered as suggestive for the space weather predictions, for turbulent cascades in different media and for the laboratory plasma confinement (e.g., for fusion devices).

Relativistic spotlight

Relativistic motion gives rise to a large number of interesting and sometimes counterintuitive effects. In this work we consider an example of such effects, which we term relativistic spotlight. When an isotropic source of soft photons with proper intensity I0 is placed at rest between a distant observer and photosphere of relativistic wind, its intensity as seen by the observer gets enhanced up to ∼Γ4I0, where Γ is bulk Lorentz factor of the wind. In addition, these photons may extract a large part of the wind kinetic energy. We speculate that such effect may be relevant for the physics of cosmic Gamma-Ray Bursts.

Design of an Oscillating Coil Pendulum Energy Generating System

The purpose of this paper is to study the theocratical work for a new type of wind power system. This wind system, called Wing oscillating coil rod pendulum system. This is a small prototype that generates low current and voltage. This system is a new type of wind turbine, to generate energy by using wind. One of the main elements of this system is a copper coil pendulum with flapping wing attached to it which oscillates at a low frequency when wind strikes it. The wind blowing kinetic energy compels the pendulum to oscillate, so the kinetic energy of wind is converted into oscillating energy of pendulum. The oscillating energy is then converted into electrical energy by using a semicircle shaped permanent magnet, which is placed under the coil rod pendulum. Theocratical construction and electrical design of wing oscillating coil rod pendulum system is discussed in this paper.

Design and Manufacturing of Wind Turbine Blades of Low Capacity Using CAD/CAM Techniques and Composite Materials

This paper proposes a methodology for design and manufacturing of wind turbine blades of low capacity with CAD (Computer Aided Design)/ CAM (Computer Aided Manufacturing) techniques and composite materials. The design of the blades was performed with help of specialized software, one of them developed in the author's institution (TIMEO®). The manufacturing of the blades model was executed in a machining center of three axes CNC, DYNA MYTE DM-4800. The final manufacture of composite materials was performed.The wind energy is an indirect form of the solar energy, since they are the temperature differences and the pressure-induced in the atmosphere by absorbing solar radiation, which set in motion the winds. The rotor mission in a wind turbine is transforming this kinetic energy of wind to mechanic energy. In this paper the design of the blades is based on the blade element moment theory. For the design and manufacturing CAD/CAM was developed a general methodology. In manufacturing of the blade was necessary to manufacture a false bed, which was used as a virtual axis, this is because the milling machine where this was manufactured only has three axes.The mechanical efficiency of a wind turbine depends on other factors airfoil blade, since the aerodynamic forces that occur in this provides the torque necessary for rotating the electric generator. In this sense, obtaining highly accurate airfoil geometries helps to improve the efficiency of the wind machine.Blades were manufactured of length 75.5cm, for a 600 watts wind turbine power, the design parameters were based on the environmental conditions of the coast of Michoacán, Mexico. The machining of the blades model are made from wood by mechanical milling, which is a manufacturing process for metal removal performed by the motion of a rotating cutting tool called milling cutter. The final manufacture of fiberglass performed and in which an internal structure is proposed to provide the parameters necessary rigidity and flexibility.The results obtained show that is feasible the manufacture of this type of mechanical elements through these techniques. We show that the precise control of geometry directly impacts in the aerodynamic efficiency of wind machine.

Studying an interaction between tropical cyclones and jet streams using the numerical simulation data

Discussed are the results of studying an evolution of tropical cyclones (TCs) in the Pacific Ocean using the data of computation of ETA and WRF NMM mesoscale numerical atmospheric models. Computed are the trajectories of TCs and the fields of meteorological variables in the typhoons, of the wind speed and kinetic energy in the subtropical jet stream during the development of Parma, Melor, and Lupit typhoons. Carried out are the analysis and comparison of computed fields of pressure, wind, kinetic energy, and trajectories of TCs obtained using these models and their comparison with the actual fields. It is demonstrated that both models computed rather well the complex trajectories and the fields of wind and kinetic energy varying in the course of the interaction. Proposed is an explanation of processes taking place during the interaction between the vortices and the subtropical jet stream and the polar front.

Inter Laminar Failure Characterization Using Refined Delamination Factor in Composite Wind Turbine Blade

The role of power extracted from “wind turbine” cannot be excluded from the context of power extraction from the renewable sources of energy. Rotating blades of the turbine convert the kinetic energy of wind into useful power. Utilization of renewable wind energy in India has increased many fold from the last decade of the 20th century. The wind turbine blades were fabricated using glass fiber reinforced composite materials. To improve the strength of the blades under varying loading conditions, spars were embedded in it. The spars were fastened with the composite shells of the blades using bolted connections. As to affect this fastening, holes of appropriate size were drilled in the composite laminates. Drilling is most widely applied to composite materials; but damage induced by this operation may reduce drastically the component performance. For establishing the damage level, delamination was measured quantitatively using digital means. A comparison between existing conventional (FD) and adjusted (FDA) delamination factor is presented with the proposed refined delamination factor (FDR). The accuracy of the proposed criteria was validated using the experimental results.

Optimization of Aerodynamic Performance of Wind Turbine Blades

A wind-power generation system uses wind turbine blades to convert the kinetic energy of wind to drive a generator which in turn yields electricity, the aerodynamic performance of the wind turbine blades has decisive effect on the cost benefit of the whole system. The aerodynamic analysis and the optimization of design parameters for the wind turbine blades are key techniques in the early stage of the development of a wind-power generation system. It influences the size selection of connecting mechanisms and the specification of parts in the design steps that follows. A computational procedure and method for aerodynamics optimization was established in this study for three-dimensional blades and the rotor design of a wind turbine. The procedure was applied to improving a previously studied 25kW wind turbine rotor design. Results show that the aerodynamic performance of the new three-dimensional blades has remarkable improvement after optimization.

Utilizing Kinetic Energy of Wind as a Source of Power in Commercial Vehicles

This project is about using kinetic energy of wind in a vehicle moving at a high speed for generation of electricity. This can be achieved by installing a housing on top of the vehicle which will contain an air duct of varying cross sectional area, a turbine and generator. This project gives information about where and how these components should be installed to produce maximum power. This article also gives information about limitations of this project and explains its drawbacks. The model is designed using Autodesk INVENTOR Professional.

A digital image analysis to evaluate delamination factor for wind turbine composite laminate blade

Kinetic energy of wind is converted into useful power by the rotation of blades that are fabricated using glass fiber reinforced composite. Bolted connections are used to fasten the spares with composite shells of the blades. In order the effect this fastening, holes of appropriate size are drilled in the composite laminates. Drilling in composite material is a common phenomena. However the damage caused in the material during drilling results in a drastical reduction of the performance of the component. A newer quantitative digital measurement model is generated using Buckingham’s π theorem to characterize the damage level, termed as refined delamination factor (FDR). Along with FDR, a comparison of FD and FDA is presented. Experimental results are used to validate the accuracy of proposed criteria.