Nonlinear Flutter Analysis of a Bend-Twist coupled Composite Wind Turbine Blade in Time Domain

The aeroelasticity and the flutter of the wind turbine blade have been emphasized by related fields. The flutter of the wind turbine blade airfoil and its condition will be focused on. The eigenvalue method and the time domain analysis method will be used to solve the flutter of the wind turbine blade airfoil respectively. The flutter problem will be firstly solved using eigenvalue approach. The flutter region, where the flutter will occur and anti-flutter region, where the flutter will not occur, will be obtained directly by judging the sign of the real part of the characteristic roots of the blade system. Then the time domain analysis of flutter of wind turbine blade will be carried out through the use of the four-order Runge-Kutta numerical methods, the flutter region and the anti-flutter region will be gotten in another way. The time domain analysis can give the changing treads of the aeroelastic responses in great detail than those of the eigenvalue method. The flap displacement of wind turbine blade airfoil will change from convergence to divergence, and change from divergence to convergence extremely suddenly. During the flutter region, the flutter of wind turbine blade will occur extremely dramatically. The flutter region provided by the time domain analysis of the flutter of the blade airfoil accurately coincides with the results of eigenvalue approach, therefore the simulation results are reliable and credible.

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Modelling of anisotropic beam for rotating composite wind turbine blade by using finite-difference time-domain (FDTD) method

Renewable Energy ◽

10.1016/j.renene.2020.10.007 ◽

2020 ◽

Vol 162 ◽

pp. 2361-2379

Author(s):

Hang Meng ◽

Fue-Sang Lien ◽

Eugene Yee ◽

Jingfang Shen

Keyword(s):

Finite Difference ◽

Wind Turbine ◽

Turbine Blade ◽

Time Domain ◽

Finite Difference Time Domain ◽

Fdtd Method ◽

Wind Turbine Blade ◽

Difference Time

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Analysis of Time Domain Active Sensing Data from CX-100 Wind Turbine Blade Fatigue Tests for Damage Assessment

Journal of the Korean Society for Nondestructive Testing ◽

10.7779/jksnt.2016.36.2.93 ◽

2016 ◽

Vol 36 (2) ◽

pp. 93-101

Author(s):

Mijin Choi ◽

Hwee Kwon Jung ◽

Stuart G. Taylor ◽

Kevin M. Farinholt ◽

Jung-Ryul Lee ◽

...

Keyword(s):

Wind Turbine ◽

Turbine Blade ◽

Time Domain ◽

Damage Assessment ◽

Fatigue Tests ◽

Wind Turbine Blade ◽

Active Sensing ◽

Sensing Data

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Diagnosis of damaged wind turbine blade by noise characteristics

Noise Control Engineering Journal ◽

10.3397/1/376813 ◽

2020 ◽

Vol 68 (2) ◽

pp. 146-156

Author(s):

Chao-Nan Wang ◽

Tang-Yao Chi

Keyword(s):

Feature Extraction ◽

Wind Turbine ◽

Turbine Blade ◽

Frequency Analysis ◽

Time Domain ◽

Wind Turbine Blade ◽

Statistical Regression ◽

Time Frequency Analysis ◽

Time Frequency ◽

Noise Characteristics

This study has proposed two estimation models of noise signal characteristic diagnosis based on time-domain and time-frequency analysis. The diagnosis of time domain was based on the fractal theory, and the result of fractal dimensions was converted into Gauss distribution, so as to provide a feature extraction for abnormality diagnosis of damaged blade. In addition, for time-frequency analysis, the wavelet methodwas used as the basis of signal analysis. The Morlet transform and mother wavelet were used for wavelet analysis of signal to obtain the result of time-frequency analysis. When the time axis was integrated, the marginal spectrum of frequency domain was obtained, and statistical regression analysis was used to provide another method of feature extraction diagnosis. The wind turbine blade signal was measured in actual wind turbine operation at Changhua Coastal Industrial Park for diagnostic analysis, so as to provide a multi-diagnostic model of wind turbine blade prewarning and health management models.

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Flutter analysis of wind turbine blade with carbon nanotube reinforced vinyl ester

Materials Today Proceedings ◽

10.1016/j.matpr.2021.04.574 ◽

2021 ◽

Author(s):

Teh Kai Yuan ◽

Saravana Kannan Thangavelu ◽

Charlie Chin Voon Sia ◽

Kok Hing Chong

Keyword(s):

Carbon Nanotube ◽

Wind Turbine ◽

Turbine Blade ◽

Vinyl Ester ◽

Wind Turbine Blade ◽

Flutter Analysis

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Flutter Analysis of Piezoelectric Material Based Smart Wind Turbine Blade

10.20855/ijav.2021.26.31787 ◽

2021 ◽

Vol 26 (3) ◽

pp. 240-247

Author(s):

Hao Wang ◽

Junyu Yi ◽

Wei Chen ◽

Zhexin Zhou

Keyword(s):

Wind Turbine ◽

Piezoelectric Material ◽

Critical Velocity ◽

Turbine Blade ◽

Unsteady Aerodynamics ◽

Wind Turbine Blade ◽

Mass Ratio ◽

Electrical Load ◽

Flutter Analysis ◽

Simulation Results

This paper presents a smart wind turbine blade of piezoelectric material. Based on Theodorsen unsteady aerodynamics and the V-g method, the flutter analysis in frequency domain is carried out for the smart wind turbine blade and the ordinary wind turbine blade. The simulation results demonstrate that the flutter critical velocity, that is, the reduced velocity of the smart wind turbine blade, is obviously much higher than that of the ordinary wind turbine blade. The smart wind turbine blade of piezoelectric material can effectively restrain the flutter of the wind turbine blade, especially for the flap motion. For the torsion motion, the smart wind turbine blade is kept away from the critical flutter. Then, to investigate the influences of different parameters on the flutter of the smart wind turbine blade, the influences of the center of gravity, the frequency ratio and the mass ratio of the blades on the flutter critical velocity of the smart wind turbine blade are researched respectively. The increase of the applied external electrical load of the piezoelectric material can increase the flutter critical velocity of the smart wind turbine blade.

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The Analysis of the Flutter Region of Wind Turbine Blade

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.423-426.1520 ◽

2013 ◽

Vol 423-426 ◽

pp. 1520-1523

Author(s):

Hao Wang ◽

Bing Ma ◽

Jiao Jiao Ding

Keyword(s):

Wind Turbine ◽

Turbine Blade ◽

Aerodynamic Force ◽

Angular Displacement ◽

Wind Turbine Blade ◽

Speed Ratio ◽

Tip Speed Ratio ◽

Flutter Analysis ◽

The Given

As the wind turbine blade is becoming larger and larger, the flutter of the wind turbine blade has been paid great attention by many fields. The flutter region of the wind turbine blade airfoil was focused on. The equation of motion for the flutter of blade airfoil was established, based on the simplified aerodynamic force and torque. The flutter analysis of wind turbine blade was carried out with the four-order Runge-Kutta methods, and so the flutter region of the blade airfoil can be obtained. The results show that, there are two critical tip speed ratios for the given blade airfoil. When the tip speed ratio is below the low critical speed ratio, the blade airfoil is convergent. At the low tip speed ratio, the blade airfoil system will become divergent from convergent condition. When the tip speed ratio is between the low critical tip speed ratio and the high one, the blade airfoil system will diverge. At the high tip speed ratio, the system will become convergent from divergent condition. When the tip speed ratio is above the high critical tip speed ratio, the blade airfoil system will converge again. In addition, the torsional angular displacement and velocity always keep convergent, the flap velocity is slightly divergent, because they are not sensible to the change of the tip speed ratio, and they are difficult to cause flutter, so the torsional motion will be more stable than flap motion for the given blade airfoil. It can provide one of references for the determination of the blade airfoil.

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