Vibration Characteristics of an Experimental Wind Turbine with a 15m Teetered Rotor.

Wind turbine is the high-end and important equipment, of which the reliability and stability is always one of the main problems. Because the gearbox is running under the condition of dynamic load caused by random wind speed, it has important significance for improving reliability of the transmission system to research dynamic behaviors of wind turbine gearbox, especially the vibration characteristics. First of all, time-varying stiffness of the meshing gear-pair is calculated in this article. Then the dynamic model of parallel gears is established and the corresponding vibration characteristics are simulated. Finally, the conclusion that the speed increasing gearbox has the amplified effect on vibration displacement disturbance and the speed decreasing gearbox has the diminished effect on vibration displacement disturbance is drawn from the contrastive analysis of vibration characteristics for these two gearboxes.

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Flexible and Vibration Characteristics Simulation for the Large Megawatt Size Wind Turbine Blades

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.217-218.363 ◽

2011 ◽

Vol 217-218 ◽

pp. 363-367

Author(s):

Xu Dong Wang ◽

Li Cun Wang ◽

Xian Ming Zhang ◽

Jun Feng

Keyword(s):

Wind Turbine ◽

Wind Power ◽

Turbine Blades ◽

Vibration Characteristics ◽

Wind Turbine Blades ◽

Fatigue Lifetime ◽

Aeroelastic Model ◽

Blade Tip ◽

Important Significance ◽

Blade Element

In the development of new large megawatt size wind turbines, aerodynamic and structural reserch is interesting and important for study wind turbine performace and boost the development of wind power. In this paper, the aerodynamic and aeroelastic characteristic of blades is investigated and presented based on Blade Element Momentum and Hamilton theory. Then the flexible characteristics of balde is researched with the aerodynamic and aeroelastic model of the rotor. The flapwise and edgewise displacements, velocities and accelerations of blade tip are simulated and plotted to validate the model which is presented in this paper. The results have very important significance to investigate the vibration and fatigue lifetime of the wind turbine blades.

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Analysis on Vibration Characteristics of Wind Turbine Blade to Improve the Effectiveness through CFD Developed by ANSYS

Materials Science Forum ◽

10.4028/www.scientific.net/msf.937.43 ◽

2018 ◽

Vol 937 ◽

pp. 43-50

Author(s):

M. Rajaram Narayanan ◽

S. Nallusamy

Keyword(s):

Shape Memory Alloys ◽

Shape Memory ◽

Wind Turbine ◽

Natural Frequency ◽

Turbine Blade ◽

Turbine Blades ◽

Vibration Characteristics ◽

Wind Turbine Blade ◽

Horizontal Axis Wind Turbine ◽

Damping Material

In the current scenario, there is a continuous need for increasing the efficiency of the aerodynamics of wind turbine blades through research studies. Vibration in a wind turbine blade has lot to do on its performance. An effective approach is required by wind mill including to control the vibration to achieve better results. The objective of this research is to investigate the vibration characteristics of the prototype horizontal axis wind turbine blade developed by using 3D modelling software. Shape memory alloys with their variable material properties offer an alternative adaptive mechanism hence it is used as a damping material. A prototype blade with S1223 profile was manufactured and the natural frequency was found over the surface of the blade. Similarly, results were studied by increasing the number of alloys wires over the blade up to three. Results showed that the embedment of shape memory alloys over the blade’s surface increases the natural frequency and reduce the amplitude of vibration because of super elastic nature of alloys. Also it was observed that the natural frequency increased by 6% and reduced the amplitude by about 93% where three wires of 0.5mm diameter were kept for the length of 720mm.

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A New Identification Method for Bolt Looseness in Wind Turbine Towers

Shock and Vibration ◽

10.1155/2019/6056181 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

He Xianlong ◽

She Tianli

Keyword(s):

Wind Turbine ◽

Phase Difference ◽

Damping Ratio ◽

Research Result ◽

Vibration Characteristics ◽

First Order ◽

Before And After ◽

Wind Turbine Towers ◽

Vibration Tests ◽

Experimental Data Analysis

Flange plates are key joining components used in wind turbine towers. Bolt looseness results in common fatigue damage in wind turbine towers. Detailed vibration tests were carried out on six wind turbine towers with loose bolts. First, the bolt looseness situation of each wind turbine tower was detected by the torque method. The vibration characteristics of each tower were then tested and analyzed in detail before maintenance. Finally, the vibration characteristics were tested and analyzed in detail after maintenance. The experimental data analysis shows that the first-order natural frequencies of the wind turbine towers before and after bolt maintenance do not change; the damping ratio does not change significantly; and the first-order vibration mode remains effectively unchanged. The phase difference between the upper and the lower plates of a flange has a significant and abrupt characteristic even when the bolt looseness ratio is 6%; however, the phase difference does not exhibit this characteristic after the flange bolts are retightened. The experimental results show that compared with other vibration characteristics, the first-order phase difference characteristic of wind turbine towers is more markedly affected by the looseness of the flange bolts; hence, this characteristic can be used as a diagnostic that reflects flange bolt looseness. Whether the flange bolts of a given tower require tightening can be identified based on whether the absolute value of the phase difference between the upper and lower plates of the flanges suddenly increases. This research result can provide a new method for the identification of bolt looseness in wind turbine towers.

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Vibration characteristics of a large wind turbine tower on non-rigid foundations

10.2172/7105683 ◽

1977 ◽

Author(s):

S. T. Yee ◽

T. Y.P. Chang ◽

R. J. Scavuzzo ◽

D. H. Timmerman ◽

J. W. Fenton

Keyword(s):

Wind Turbine ◽

Vibration Characteristics ◽

Wind Turbine Tower ◽

Large Wind

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