Flapwise and Edgewise Blade Loads Analysis of HAWT Rotor by Using Fluid-Oscillation Coupled Calculation Model

2011 ◽  
Author(s):  
Yutaka Hasegawa ◽  
Yusuke Takagi ◽  
Junsuke Murata ◽  
Koji Kikuyama
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Calculation Model ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Aerodynamic Loads ◽  
Coupled Calculation ◽  
Fluid Oscillation ◽  
Fatigue Loads ◽  
Inflow Conditions

A horizontal axis wind turbine suffers fluctuating aerodynamic loads, which result in oscillations of the rotor blades. Since the blade oscillation has considerable effects on the blade fatigue life, the influence on the fatigue loads from the interaction between the aerodynamic loads and the structural oscillations should be considered in the design process of the wind turbine rotor. The objective of this work is to analyze the aerodynamic effects on the fatigue loads of rotor blade due to structural oscillation and inflow conditions, by using numerical calculation method. This paper explains a calculation model which can estimate the aerodynamic loads on the rotor blade of the horizontal axis wind turbine in the inflow conditions with the turbulence and yawed misalignment. The fluid-oscillation coupled calculation has been performed for the geometry of the NREL test turbine. The calculated results are compared with the experimental results to evaluate the validity of the calculation model.

scholarly journals Influence of the Heights of Low-Level Jets on Power and Aerodynamic Loads of a Horizontal Axis Wind Turbine Rotor

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 132 ◽  
Author(s):  
Xuyao Zhang ◽  
Congxin Yang ◽  
Shoutu Li
Keyword(s):  
Wind Speed ◽  
Power Spectrum ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Aerodynamic Loads ◽  
Low Level ◽  
Low Level Jets ◽  
Inflow Conditions ◽  
Swept Area

The influence of the heights of low-level jets (LLJs) on the rotor power and aerodynamic loads of a horizontal axis wind turbine were investigated using the fatigue, aerodynamics, structures, and turbulence code. The LLJ and shear inflow wind fields were generated using an existing wind speed spectral model. We found that the rotor power predicted by the average wind speed of the hub height is higher than the actual power in relatively weak and shallow LLJ inflow conditions, especially when the LLJ height is located inside the rotor-swept area. In terms of aerodynamic loads, when the LLJ height is located inside the rotor-swept area, the root mean square (RMS) rotor thrust coefficient and torque coefficient increase, while the RMS rotor unbalanced aerodynamic load coefficients, including lateral force, longitudinal force, tilt moment, and yaw moment, decreased. This means that the presence of both positive and negative wind shear in the rotor-swept area not only increases the rotor power but also reduces the unbalanced aerodynamic loads, which is beneficial to the operation of wind turbine. Power spectrum analysis shows no obvious difference in the power spectrum characteristics of the rotor torque and thrust in LLJ inflow conditions with different heights.

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.

scholarly journals Clarification of influences of inflow conditions on wake of horizontal axis wind turbine

2015 ◽  
Vol 81 (825) ◽  
pp. 14-00592-14-00592
Author(s):  
Manhae HAN ◽  
Takao MAEDA ◽  
Yasunari KAMADA ◽  
Junsuke MURATA ◽  
Koki MURAKAMI
Keyword(s):  
Wind Turbine ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Inflow Conditions

337 Aerodynamic Loads on Horizontal Axis Wind Turbine Rotors Exerted by Wind Gust

2005 ◽  
Vol 2005.2 (0) ◽  
pp. 245-246
Author(s):  
Shinya HOTTA ◽  
Yutaka HASEGAWA ◽  
Hiroshi IMAMURA ◽  
Junsuke MURATA ◽  
Koji KIKUYAMA
Keyword(s):  
Wind Turbine ◽  
Horizontal Axis ◽  
Wind Gust ◽  
Horizontal Axis Wind Turbine ◽  
Aerodynamic Loads ◽  
Turbine Rotors

scholarly journals Geometrical Design of a Rotor Blade for a Small Scale Horizontal Axis Wind Turbine

2019 ◽  
Vol 8 (3) ◽  
pp. 3390-3400
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Operating Conditions ◽  
Horizontal Axis ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Geometrical Properties ◽  
Momentum Theory ◽  
Bem Theory ◽  
Blade Element

In the present study, Blade Element Momentum theory (BEMT) has been implemented to heuristically design a rotor blade for a 2kW Fixed Pitch Fixed Speed (FPFS) Small Scale Horizontal Axis Wind Turbine (SSHAWT). Critical geometrical properties viz. Sectional Chord ci and Twist distribution θTi for the idealized, optimized and linearized blades are analytically determined for various operating conditions. Results obtained from BEM theory demonstrate that the average sectional chord ci and twist distribution θTi of the idealized blade are 20.42% and 14.08% more in comparison with optimized blade. Additionally, the employment of linearization technique further reduced the sectional chord ci and twist distribution θTi of the idealized blade by 17.9% and 14% respectively, thus achieving a viable blade bounded by the limits of economic and manufacturing constraints. Finally, the study also reveals that the iteratively reducing blade geometry has an influential effect on the solidity of the blade that in turn affects the performance of the wind turbine.

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