Nonlinear Dynamic Response of a Wind Turbine Rotor under Gravitational Loading

AIAA Journal ◽  
1978 ◽  
Vol 16 (8) ◽  
pp. 773-774 ◽  
Author(s):  
Inderjit Chopra ◽  
John Dugundji
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Nonlinear Dynamic ◽  
Turbine Rotor ◽  
Nonlinear Dynamic Response ◽  
Gravitational Loading ◽  
Wind Turbine Rotor

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.

Analysis of Nonlinear Dynamic Response of Wind Turbine Blade Under Fluid–Structure Interaction and Turbulence Effect

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Jianping Zhang ◽  
Kaige Zhang ◽  
Aixi Zhou ◽  
Tingjun Zhou ◽  
Danmei Hu ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Nonlinear Dynamic ◽  
Fluid Structure Interaction ◽  
Wind Turbine Blade ◽  
Response Curves ◽  
Nonlinear Dynamic Response ◽  
Structure Interaction ◽  
Turbulence Effect

In this paper, the entity model of a 1.5 MW offshore wind turbine blade was built by Pro/Engineer software. Fluid flow control equations described by arbitrary Lagrange–Euler (ALE) were established, and the theoretical model of geometrically nonlinear vibration characteristics under fluid–structure interaction (FSI) was given. The simulation of offshore turbulent wind speed was achieved by programming in Matlab. The brandish displacement, the Mises stress distribution and nonlinear dynamic response curves were obtained. Furthermore, the influence of turbulence and FSI on blade dynamic characteristics was studied. The results show that the response curves of maximum brandish displacement and maximum Mises stress present the attenuation trends. The region of the maximum displacement and maximum stress and their variations at different blade positions are revealed. It was shown that the contribution of turbulence effect (TE) on displacement and stress is smaller than that of the FSI effect, and its extent of contribution is related to the relative span length. In addition, it was concluded that the simulation considering bidirectional FSI (BFSI) can reflect the vibration characteristics of wind turbine blades more accurately.

Dynamics-Based Health Monitoring of Wind Turbine Rotor Blades Using Integrated Inertial Sensors

2012 ◽  
Author(s):  
Scott R. Dana ◽  
Douglas E. Adams
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Modal Analysis ◽  
Turbine Rotor ◽  
Vertical Shear ◽  
Aerodynamic Load ◽  
Test Bed ◽  
Horizontal Axis Wind Turbine ◽  
Structural Dynamic ◽  
Wind Turbine Rotor

By analyzing the rotor structural dynamic response of a wind turbine, this research aims to improve decision making in operation and maintenance. To illustrate the potential of this measurement technique, a horizontal axis wind turbine test-bed is used to experimentally simulate the rotor structural dynamic response to uniform flow as well as horizontal and vertical shear flow across the rotor plane. The structural dynamic characteristics of the wind turbine rotor are described in the context of modal analysis where each mode of vibration occurs at a particular frequency with a particular modal deflection shape. These deflection shapes facilitate the effectiveness with which a given aerodynamic load couples into the rotor to produce mechanical power in addition to vibrations of the rotor. Operational modal analysis is used to explore the effects of changes in the wind state on the sensitivity of condition monitoring data to two types of damages in the turbine rotor, ice accretion and blade root cracking. Additionally, the degree to which various damage mechanisms can be identified in the presence of yaw and pitch set points is analyzed. It is shown that certain frequencies in the measured response using the flap, edgewise, and span directions of the wind turbine are sensitive to a change in condition of the rotor for use in detecting that type of damage. By analyzing the changes in the modal response amplitudes, the type of damage present in the rotor system can also be classified.

Harmonization of new wind turbine rotor blades development process: A review

2014 ◽  
Vol 39 ◽  
pp. 874-882 ◽  
Author(s):  
B. Rašuo ◽  
M. Dinulović ◽  
A. Veg ◽  
A. Grbović ◽  
A. Bengin
Keyword(s):  
Wind Turbine ◽  
Development Process ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Wind Turbine Rotor
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