Prediction of stresses and natural frequencies for high speed wind turbine blades

1979 ◽  
Author(s):  
F. PERKINS ◽  
D. CROMACK
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Wind Turbine Blades

Design and Research on a Automatic Cleaning Device of Wind Turbine Blades

2013 ◽  
Vol 448-453 ◽  
pp. 3472-3475
Author(s):  
Tai Lv ◽  
Qiang Wang
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Pressure Field ◽  
Turbine Blades ◽  
Positive Pressure ◽  
Wind Turbine Blades ◽  
Cleaning Device ◽  
Horizontal Axis Wind Turbines ◽  
Ash Deposit ◽  
Fluent Software

Aiming at ash deposit problem of wind turbine blades, a cleaning device for 10kW horizontal axis wind turbines was designed by applying the mechanism that ash deposit on blades surface was purged by high-speed flows from nozzle. Using fluent software, a numerical simulation was carried out in cleaning device, and its pressure field and velocity field in different cross section of wind turbine blades were simulated under cleaning state. The results showed that positive pressure zone created by cleaning device was formed on blades surface, and high-speed airflow purging blades surface was formed. As a result, the purpose of cleaning is achieved.

scholarly journals Wind Turbine Aerodynamic Performance by Lifting Line Method

1998 ◽  
Vol 4 (3) ◽  
pp. 141-149 ◽  
Author(s):  
Horia Dumitrescu ◽  
Vladimir Cardos
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Turbine Blades ◽  
Numerical Data ◽  
Computational Effort ◽  
Horizontal Axis ◽  
Wind Turbine Blades ◽  
Horizontal Axis Wind Turbine ◽  
Trailing Vortices ◽  
Free Wake

The vortex model of propellers is modified and applied to the high-speed horizontal axis turbines. The turbine blades are replaced by lifting lines and trailing vortices which shed along the blade span. The model is not a free wake model, but it is still a nonlinear one which should be solved iteratively. In addition to the regular case where the trailing vortices are constrained to distribute along a helical surface, another version, where each trailing vortex sheding from the blade grows as a free helical vortex line, is also included. Performance parameters are calculated by application of the Biot-Savart law along with the Kutta-Joukowski theorem. Predictions are, shown to compare favorably with existing numerical data from more involved free wake methods, but require less computational effort. Thereby, the present method may be a very useful tool for calculating the aerodynamic loads on horizontal-axis wind turbine blades.

The influence of rotation on natural frequencies of wind turbine blades with pre-bend

2020 ◽  
Vol 12 (2) ◽  
pp. 023303
Author(s):  
Jin Xu ◽  
Lei Zhang ◽  
Shuang Li ◽  
Jianzhong Xu
Keyword(s):  
Wind Turbine ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Wind Turbine Blades

scholarly journals Identification of ice mass accumulated on wind turbine blades using its natural frequencies

2017 ◽  
Vol 42 (1) ◽  
pp. 66-84 ◽  
Author(s):  
Sudhakar Gantasala ◽  
Jean-Claude Luneno ◽  
Jan-Olov Aidanpää
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Wind Turbine ◽  
Network Model ◽  
Neural Network Model ◽  
Artificial Neural Network Model ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Explicit Relation

This work demonstrates a technique to identify information about the ice mass accumulation on wind turbine blades using its natural frequencies, and these frequencies reduce differently depending on the spatial distribution of ice mass along the blade length. An explicit relation to the natural frequencies of a 1-kW wind turbine blade is defined in terms of the location and quantity of ice mass using experimental modal analyses. An artificial neural network model is trained with a data set (natural frequencies and ice masses) generated using that explicit relation. After training, this artificial neural network model is given an input of natural frequencies of the iced blade (identified from experimental modal analysis) corresponding to 18 test cases, and it identified ice masses’ location and quantity with a weighted average percentage error value of 17.53%. The proposed technique is also demonstrated on the NREL 5-MW wind turbine blade data.

Quick Method for Aeroelastic and Finite Element Modeling of Wind Turbine Blades

2014 ◽  
Author(s):  
Jeffrey Bennett ◽  
Robert Bitsche ◽  
Kim Branner ◽  
Taeseong Kim
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Wind Turbine ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Element Model ◽  
Wind Turbine Blades ◽  
Quick Method ◽  
Cross Sectional ◽  
Aeroelastic Simulations

In this paper a quick method for modeling composite wind turbine blades is developed for aeroelastic simulations and finite element analyses. The method reduces the time to model a wind turbine blade by automating the creation of a shell finite element model and running it through a cross-sectional analysis tool in order to obtain cross-sectional properties for the aeroelastic simulations. The method utilizes detailed user inputs of the structural layup and aerodynamic profile including ply thickness, orientation, material properties and airfoils to create the models. After the process is complete the user has two models of the same blade, one for performing a structural finite element model analysis and one for aeroelastic simulations. Here, the method is implemented and applied to reverse engineer a structural layup for the NREL 5MW reference blade. The model is verified by comparing natural frequencies to the reference blade. Further, the application to aeroelastic and structural evaluations is demonstrated. Aeroelastic analyses are performed, and predicted fatigue loads are presented. Extreme loads from the aeroelastic simulations are extracted and applied onto the blade for a structural evaluation of the blade strength. Results show that the structural properties and natural frequencies of the developed 5MW blade match well with the reference blade, however the structural analysis found excessive strain at 16% span in the spare caps that would cause the blade to fail.

scholarly journals Identification of Debonding Damage at Spar Cap-Shear Web Joints by Artificial Neural Network Using Natural Frequency Relevant Key Features of Composite Wind Turbine Blades

2021 ◽  
Vol 11 (12) ◽  
pp. 5327
Author(s):  
Yun-Jung Jang ◽  
Hyeong-Jin Kim ◽  
Hak-Geun Kim ◽  
Ki-Weon Kang
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Structural Integrity ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Artificial Neural ◽  
The Relationship

As the size and weight of blades increase with the recent trend toward larger wind turbines, it is important to ensure the structural integrity of the blades. For this reason, the blade consists of an upper and lower skin that receives the load directly, a shear web that supports the two skins, and a spar cap that connects the skin and the shear web. Loads generated during the operation of the wind turbine can cause debonding damage on the spar cap-shear web joints. This may change the structural stiffness of the blade and lead to a lack of integrity; therefore, it would be beneficial to be able to identify possible damage in advance. In this paper we present a model to identify debonding damage based on natural frequency. This was carried out by modeling 1105 different debonding damages, which were classified by configuration type, location, and length. After that, the natural frequencies, due to the debonding damage of the blades, were obtained through modal analysis using FE analysis. Finally, an artificial neural network was used to study the relationship between debonding damage and the natural frequencies.

Sustainable Vacuum-Infused Thermoplastic Composites for MW-Size Wind Turbine Blades—Preliminary Design and Manufacturing Issues

2005 ◽  
Vol 127 (4) ◽  
pp. 570-580 ◽  
Author(s):  
K. van Rijswijk ◽  
S. Joncas ◽  
H. E. N. Bersee ◽  
O. K. Bergsma ◽  
A. Beukers
Keyword(s):  
Wind Turbine ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Polyamide 6 ◽  
Rotor Blades ◽  
Thermoplastic Composites ◽  
Wind Turbine Blades ◽  
Design And Manufacturing ◽  
Deflection Criteria ◽  
Epoxy Systems

This paper addresses the feasibility of using innovative vacuum infused anionic polyamide-6 (PA-6) thermoplastic composites for MW-size wind turbine blades structures. To compare the performance of this fully recyclable material against commonly used less sustainable thermoset blade materials in a baseline structural MW-size blade configuration (box-spar/skins), four different blade composite material options were investigated: Glass/epoxy, carbon/epoxy, glass/PA-6, and carbon/PA-6. Blade characteristics such as weight, costs, and natural frequencies were compared for rotor blades ranging between 32.5 and 75m in length, designed according to both stress and tip deflection criteria. Results showed that the PA-6 blades have similar weights and natural frequencies when compared to their epoxy counterpart. For glass fiber blades, a 10% reduction in material cost can be expected when using PA-6 rather than epoxy while carbon fiber blades costs were found to be similar. Considering manufacturing, processing temperatures of PA-6 are significantly higher than for epoxy systems; however, the associated cost increase is expected to be compensated for by a reduction in infusion and curing time.

scholarly journals Investigation and Validation of Numerical Models for Composite Wind Turbine Blades

2021 ◽  
Vol 9 (5) ◽  
pp. 525
Author(s):  
William Finnegan ◽  
Yadong Jiang ◽  
Nicolas Dumergue ◽  
Peter Davies ◽  
Jamie Goggins
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Natural Frequencies ◽  
Numerical Models ◽  
Experimental Testing ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Static Testing ◽  
Design Life ◽  
Design And Manufacture

As the world shifts to using renewable sources of energy, wind energy has been established as one of the leading forms of renewable energy. As the requirement for wind energy increases, so too does the size of the turbines themselves, where the latest turbines are 10 MW with a turbine diameter in excess of 190 m. The design and manufacture of the blades for these turbines will be critical if they are to last for the design life, where the accuracy of the numerical models used in the design process is paramount. Therefore, in this paper, three independent numerical models have been created using three available finite element method packages—ABAQUS, ANSYS, and CalculiX—and the results were compiled. Following this, the accuracy of the models has been evaluated and validated against the results from an experimental testing campaign. In order to complete the study, a 13 m full-scale wind turbine blade has been used, which has been subjected to static testing in both the edgewise and flapwise directions. The results from this testing campaign, along with the blade mass and natural frequencies, have been compared to the results from the independent numerical models. The differences in the models, along with other sources of error, have been discussed, which includes recommendations on the development of accurate numerical models.

scholarly journals Performances and Stall Delays of Three Dimensional Wind Turbine Blade Plate-Models with Helicopter-Like Propeller Blade Tips

2017 ◽  
Vol 11 (10) ◽  
pp. 189 ◽  
Author(s):  
Sutrisno Sutrisno ◽  
Deendarlianto Deendarlianto ◽  
Indarto Indarto ◽  
Sigit Iswahyudi ◽  
Muhammad Agung Bramantya ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
High Speed ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Laminar Flows ◽  
Wind Turbine Blade ◽  
Mathematical Form ◽  
Wind Turbine Blades ◽  
Blade Tips

The research on three dimensional (3-D) wind turbine blades has been introduced (Sutrisno, Prajitno, Purnomo, & B.W. Setyawan, 2016). In the current experiment, the 3-D wind turbine blades would be fitted with helicopter-like blade tips and additional fins to the blade hubs to demonstrate some laminarizing features. It was found that additional helicopter-like blade tip to the turbine blade creates strong laminar flows over the surface of the blade tips. Supplementary, finned hub, fitted to the blade body, creates rolled-up vortex flows, weakens the blade stall growth development, especially for blades at high-speed wind. A proposed mathematical form of modified lifting line model has been developed to pursue further 3-d blade development study of 3-d wind turbine blade. Rolled up vortex effects, developed by finned of the base hub, has been acknowledged could demolish the turbulent region, as well as laminarize the stall domain to intensify the induced wind turbine blade lift.

Sign in / Sign up

Export Citation Format

Share Document