Accurate Correlation of Wind Turbine Response With Wind Speed Using a New Characterization of Turbulent Wind

1987 ◽  
Vol 109 (4) ◽  
pp. 321-329 ◽  
Author(s):  
J. R. Connell ◽  
R. L. George
Keyword(s):  
Wind Turbine ◽  
Rotor Blades ◽  
Turbulence Energy ◽  
Horizontal Axis Wind Turbine ◽  
Output Fluctuations ◽  
Wind Characteristics ◽  
Turbine Design ◽  
And Control ◽  
Fluctuating Wind

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

Calculating the aerodynamics of vertical axis wind turbines

2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc
Keyword(s):  
Wind Turbine ◽  
Incidence Angle ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Velocity Triangle ◽  
Relationship Of ◽  
The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

scholarly journals Perancangan Prototipe Turbin Angin Sumbu Horizontal Skala Laboratorium Dengan Inverter

2021 ◽  
Vol 1 (1) ◽  
pp. 24-29
Author(s):  
Najma Safienatin Najah ◽  
Arief Muliawan ◽  
Febria Anita
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Design Research ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Research Results ◽  
Turn On ◽  
Generator Voltage ◽  
Turbine Design ◽  
Generator Currents

A horizontal axis wind turbine design research has been carried out using an inverter. This study aims to generate the output power generated by the generator through an inverter. So that the use of an inverter can turn on the 10 watt lamp. From the research results obtained turbine rotation varied between 1357 rpm to 2415 rpm producing a generator voltage of 3.05 volts to 4.61 volts and generator currents 32mA up to 49 mA. The inverter produces a voltage of 16.57 volts up to 20.46 volts and an inverter current of 0.60 amperes up to 0.48 amperes. The greater the rotation of the wind turbine turbine, the greater the generator voltage generated and so is the voltage of the inverter. While the current will increase as the turbine rotation increases and the inverse of the inverter current will decrease as the turbine rotation increases.

scholarly journals Modeling and simulation of forces applied to the horizontal axis wind turbine rotors by the vortex method coupled with the method of the blade element

2021 ◽  
Vol 12 (1) ◽  
pp. 413
Author(s):  
Ibtissem Barkat ◽  
Abdelouahab Benretem ◽  
Fawaz Massouh ◽  
Issam Meghlaoui ◽  
Ahlem Chebel
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Vortex Method ◽  
Operating Conditions ◽  
Horizontal Axis ◽  
Rotor Blades ◽  
Good Representation ◽  
Horizontal Axis Wind Turbine ◽  
Blade Element

This article aims to study the forces applied to the rotors of horizontal axis wind turbines. The aerodynamics of a turbine are controlled by the flow around the rotor, or estimate of air charges on the rotor blades under various operating conditions and their relation to the structural dynamics of the rotor are critical for design. One of the major challenges in wind turbine aerodynamics is to predict the forces on the blade as various methods, including blade element moment theory (BEM), the approach that is naturally adapted to the simulation of the aerodynamics of wind turbines and the dynamic and models (CFD) that describes with fidelity the flow around the rotor. In our article we proposed a modeling method and a simulation of the forces applied to the horizontal axis wind rotors turbines using the application of the blade elements method to model the rotor and the vortex method of free wake modeling in order to develop a rotor model, which can be used to study wind farms. This model is intended to speed up the calculation, guaranteeing a good representation of the aerodynamic loads exerted by the wind.

Model Identification and Operating Load Characterization for a Small Horizontal Axis Wind Turbine Rotor Using Integrated Blade Sensors

2010 ◽  
Author(s):  
Scott Dana ◽  
Joseph Yutzy ◽  
Douglas E. Adams
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Rotor Blade ◽  
Model Identification ◽  
Turbine Rotor ◽  
Forced Response ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
And Control ◽  
Wind Turbine Rotor

One of the primary challenges in diagnostic health monitoring and control of wind turbines is compensating for the variable nature of wind loads. Given the sometimes large variations in wind speed, direction, and other operational variables (like wind shear), this paper proposes a data-driven, online rotor model identification approach. A 2 m diameter horizontal axis wind turbine rotor is first tested using experimental modal analysis techniques. Through the use of the Complex Mode Indication Function, the dominant natural frequencies and mode shapes of dynamic response of the rotor are estimated (including repeated and pseudo-repeated roots). The free dynamic response properties of the stationary rotor are compared to the forced response of the operational rotor while it is being subjected to wind and rotordynamic loads. It is demonstrated that both narrowband (rotordynamic) and broadband (wind driven) responses are amplified near resonant frequencies of the rotor. Blade loads in the flap direction of the rotor are also estimated through matrix inversion for a simulated set of rotor blade input forces and for the operational loading state of the wind turbine in a steady state condition. The analytical estimates are shown to be accurate at frequencies for which the ordinary coherence functions are near unity. The loads in operation are shown to be largest at points mid-way along the span of the blade and on one of the three blades suggesting this method could be used for usage monitoring. Based on these results, it is proposed that a measurement of upstream wind velocity will provide enhanced models for diagnostics and control by providing a leading indicator of disturbances in the loads.

Powder binders used for the manufacturing of wind turbine rotor blades. Part 1. Characterization of resin-binder interaction and preform properties

2016 ◽  
Vol 39 (3) ◽  
pp. 708-717 ◽  
Author(s):  
Stefan Schmidt ◽  
Thorsten Mahrholz ◽  
Alexandra Kühn ◽  
Peter Wierach
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Resin Binder ◽  
Wind Turbine Rotor

Design comparison of wind turbines for low wind speed

2019 ◽  
Vol 2 (3) ◽  
pp. 222-229
Author(s):  
Dena Hendriana ◽  
Eka Budiarto ◽  
Alexander Clements ◽  
Arko Djajadi
Keyword(s):  
Computer Simulation ◽  
Wind Speed ◽  
Wind Turbine ◽  
Simulation Software ◽  
The Other ◽  
Horizontal Axis Wind Turbine ◽  
Low Wind Speed ◽  
Wind Characteristic ◽  
Turbine Design ◽  
Very High

Wind energy is one of the potential renewable energy, but the applications have to beadjusted to the available wind characteristic in the area. In Indonesia, the wind speed is inaverage not very high, only around 4 m/s. Therefore the wind turbine design have to be adjustedfor usage in Indonesia. In this research, two wind turbine designs are compared. One design isof the form Horizontal-Axis Wind Turbine (HAWT) and the other is of the form Vertical-AxisWind Turbine (VAWT). Both designs are optimized for wind speed of 4 m/s. The comparisonsare done using computer simulation software OpenFOAM. The result shows VAWT design canproduce similar power with smaller turbine dimension than the HAWT design.

Gyroscopic Effects of Horizontal Axis Wind Turbines Using Stochastic Aeroelasticity via Spinning Finite Elements

2012 ◽  
Author(s):  
Antonio Velazquez ◽  
R. Andrew Swartz
Keyword(s):  
Wind Turbine ◽  
Dynamic Condition ◽  
The Body ◽  
Horizontal Axis ◽  
Rotor Blades ◽  
Mathematical Framework ◽  
Horizontal Axis Wind Turbine ◽  
Study Results ◽  
Out Of Plane ◽  
Gyroscopic Effects

Horizontal axis wind turbine (HAWTs) structures, throughout the years, have presumed to be of relatively simple construction, but wind-induced aerodynamic vibrations, wind-field conditions, and power requirements tend to lead to the need for increasingly complicated designs. One phenomenon that requires special attention is the gyroscopic or Coriolis effect. In general, blades design codes are written to optimize for lightness and slenderness, but also to withstand excitations at high frequency. As a result, gyroscopic motion derives as a nonlinear dynamic condition in the out-of-plane direction that is difficult to characterize by means of the well-known vibrational theory that has been established for their design and analysis. The present study develops and presents a probabilistic analysis of the precession — gyroscopic — effects of a wind turbine model developed for tapered-swept cross-sections of nt degree with nonlinear variations of mass and geometry along the body of the blade. A dynamic orthogonal decoupling method is utilized to successfully perform the aeroelastic analysis by decoupling the damped-gyroscopic equations of motion, as a result of the addition of Rayleigh damping — symmetric proportional mass and stiffness — within the linear system in study. Results are valid for yaw-free rotor configurations by means of unknown and random (though bounded) yaw rates. Simultaneously, those results can easily be expanded for yaw-controlled mechanisms. The yaw-free assumption presents a higher risk of potential reliability expectations, given the stochastic impairment of the gyroscopic nature that is present for out-of-plane axis motions, requiring special attention at higher frequencies. This impairment becomes particularly troublesome for blade profiles with tapered-swept cross-section variations. This uncertainty can be minimized by incorporating a mathematical framework capable of characterizing properly the yaw action such that gyroscopic effects can be fully interpreted and diagnosed. In summary, the main goal is to decipher the complexity of gyroscopic patterns of flexible rotor blades with complex shape configurations, but also to provide substantial elements to successfully approach yaw-mechanics of tapered-swept rotor blades.

Mass and Aerodynamic Imbalance of a Horizontal Axis Wind Turbine

1998 ◽  
Vol 120 (1) ◽  
pp. 66-74 ◽  
Author(s):  
J. P. Borg ◽  
R. H. Kirchhoff
Keyword(s):  
Wind Turbine ◽  
Nonlinear Differential Equations ◽  
Perturbation Technique ◽  
Electrical Power ◽  
Rotational Frequency ◽  
Rotor Blades ◽  
Horizontal Axis Wind Turbine ◽  
Low Speed ◽  
Mass Imbalance ◽  
Operating Variables

It is very common among wind turbines of all designs that a spectral analysis of operating variables, such as yaw motion, torque, or electrical power output has a large concentration of variance at the rotational frequency of the low speed shaft. This spike in the spectrum of the operating variables has come to be known as the once per revolution response or 1P. In addition to this 1P spike, three-bladed wind turbine spectral signatures usually include the harmonic integers 2P and 3P. The two main sources of IP are mass imbalance in the rotor plane and various aerodynamic performance imbalances of the rotor blades. This paper is dedicated to determining the specific contribution of each of these sources to 1P as well as their effects on the 2P and 3P harmonics. Mass imbalance and aerodynamic imbalance issues are addressed separately so that the relative contribution of each can be quantified. The nonlinear differential equations describing the coupled azimuth and yaw motion with mass imbalance were analytically solved using a perturbation technique. A blade strip element technique was used to determine the effects of aerodynamic imbalance on 1P, 2P, and 3P fluctuations. It was found that 60 percent of the 1P low-speed shaft torque (LSST) fluctuation is due to mass imbalance and 40 percent due to aerodynamic imbalance. These results compare quite favorably with the NREL 15 kW Combined Experiment wind turbine data.

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