scholarly journals Aeroelasticity of Wind Turbines Blades Using Numerical Simulation

10.5772/52281 ◽  
2012 ◽  
Author(s):  
Drishtysingh Ramdenee ◽  
Adrian Ilinca ◽  
Ion Sorin
Keyword(s):  
Numerical Simulation ◽  
Wind Turbines

scholarly journals Numerical Simulation and Wind Tunnel Investigation on Static Characteristics of VAWT Rotor Starter with Lift-Drag Combined Structure

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6167
Author(s):  
Fang Feng ◽  
Guoqiang Tong ◽  
Yunfei Ma ◽  
Yan Li
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Speed Ratio ◽  
Static Characteristics ◽  
Torque Coefficient ◽  
Starting Characteristics ◽  
Static Torque

In order to get rid of the impact of the global financial crisis and actively respond to global climate change, it has become a common choice for global economic development to develop clean energy such as wind energy, improve energy efficiency and reduce greenhouse gas emissions. With the advantages of simple structure, unnecessary facing the wind direction, and unique appearance, the vertical axis wind turbine (VAWT) attracts extensive attention in the field of small and medium wind turbines. The lift-type VAWT exhibits outstanding aerodynamic characteristics at a high tip speed ratio, while the starting characteristics are generally undesirable at a low wind speed; thus, how to improve the starting characteristics of the lift-type VAWT has always been an important issue. In this paper, a lift-drag combined starter (LDCS) suitable for lift-type VAWT was proposed to optimize the starting characteristics of lift-type VAWT. With semi-elliptical drag blades and lift blades equipped on the middle and rear part outside the starter, the structure is characterized by lift-drag combination, weakening the adverse effect of the starter with semi-elliptical drag blades alone on the output performance of the original lift-type VAWT and improving the characteristics of the lift-drag combined VAWT. The static characteristic is one of the important starting characteristics of the wind turbine. The rapid development of computational fluid dynamics has laid a solid material foundation for VAWT. Thus the static characteristics of the LDCS with different numbers of blades were investigated by conducting numerical simulation and wind tunnel tests. The results demonstrated that the static torque coefficient of LDCS increased significantly with the increased incoming wind speed. The average value of the static torque coefficient also increased significantly. This study can provide guidelines for the research of lift-drag combined wind turbines.

Numerical Simulation of Dynamics of a Spar Type Floating Wind Turbine and Comparison With Laboratory Measurements

2016 ◽  
Author(s):  
Hyunseong Min ◽  
Cheng Peng ◽  
Fei Duan ◽  
Zhiqiang Hu ◽  
Jun Zhang
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Numerical Simulations ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Deep Water ◽  
Offshore Wind ◽  
Wind Loads ◽  
Floating Offshore Wind Turbines ◽  
The Cost

Wind turbines are popular for harnessing wind energy. Floating offshore wind turbines (FOWT) installed in relatively deep water may have advantages over their on-land or shallow-water cousins because winds over deep water are usually steadier and stronger. As the size of wind turbines becomes larger and larger for reducing the cost per kilowatt, it could bring installation and operation risks in the deep water due to the lack of track records. Thus, together with laboratory tests, numerical simulations of dynamics of FOWT are desirable to reduce the probability of failure. In this study, COUPLE-FAST was initially employed for the numerical simulations of the OC3-HYWIND, a spar type platform equipped with the 5-MW baseline wind turbine proposed by National Renewable Energy Laboratory (NREL). The model tests were conducted at the Deepwater Offshore Basin in Shanghai Jiao Tong University (SJTU) with a 1:50 Froude scaling [1]. In comparison of the simulation using COUPLE-FAST with the corresponding measurements, it was found that the predicted motions were in general significantly smaller than the related measurements. The main reason is that the wind loads predicted by FAST were well below the related measurements. Large discrepancies are expected because the prototype and laboratory wind loads do not follow Froude number similarity although the wind speed was increased (or decreased) in the tests such that the mean surge wind force matched that predicted by FAST at the nominal wind speed (Froude similarity) in the cases of a land wind turbine [1]. Therefore, an alternative numerical simulation was made by directly inputting the measured wind loads to COUPLE instead of the ones predicted by FAST. The related simulated results are much improved and in satisfactory agreement with the measurements.

Numerical Simulation for the Starting Characteristics of a Wind Turbine

2020 ◽  
Vol 38 ◽  
pp. 215-221
Author(s):  
Anna Kuwana ◽  
Xue Yan Bai ◽  
Dan Yao ◽  
Haruo Kobayashi
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Optimum Shape ◽  
Blade Thickness ◽  
Basic Characteristics ◽  
Starting Characteristics

There are many types of wind turbine. Large propeller-type wind turbines are used mainly for large wind farms and offshore wind power generation. Small vertical-axis wind turbines (VAWTs) are often used in distributed energy systems. In previous studies on wind turbines, the basic characteristics such as torque coefficient have often been obtained during rotation, with the turbine rotating at a constant speed. Such studies are necessary for the proper design of wind turbines. However, it is also necessary to conduct research under conditions in which the wind direction and wind speed change over time. Numerical simulation of the starting characteristics is carried out in this study. Based on the flow field around the wind turbine, the force required to rotate the turbine is calculated. The force used to stop the turbine is modeled based on friction in relation to the bearing. Equations for the motion of the turbine are solved by their use as external force. Wind turbine operation from the stationary state to the start of rotation is simulated. Five parameters, namely, blade length, wind turbine radius, overlap, gap, and blade thickness, are changed and the optimum shape is obtained. The simulation results tend to qualitatively agree with the experimental results for steadily rotating wind turbines in terms of two aspects: (1) the optimal shape has an 20% overlap of the turbine radius, and (2) the larger the gap, the lower the efficiency.

Numerical Simulation on the Flow Control by Mounting Indented Gurney Flaps for a Wind Turbine

2012 ◽  
Vol 512-515 ◽  
pp. 623-627 ◽  
Author(s):  
Wan Li Zhao ◽  
Xiao Lei Zheng
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Numerical Investigation ◽  
Wind Turbines ◽  
Aerodynamic Performance ◽  
Optimal Position ◽  
Gurney Flaps ◽  
Turbine Performance ◽  
Gurney Flap ◽  
Practical Engineering

Numerical investigation of large thick and low Reynolds airfoil of wind turbines by mounting indented Gurney flaps was carried out. The influenced rules of the position of Gurney flaps on the aerodynamic performance of airfoil under same height of flaps were achieved, and the optimal position of Gurney flap was presented. At last, the mechanism of wind turbine performance controlled by Gurney flap was discussed. The results can provide the theoretical guidance and technical support to wind turbines control in practical engineering.

Numerical Simulation and Virtual Reality Visualization of Horizontal and Vertical Axis Wind Turbines

2011 ◽  
Author(s):  
Nan Yan ◽  
Tyamo Okosun ◽  
Sanjit K. Basak ◽  
Dong Fu ◽  
John Moreland ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Virtual Reality ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Small Scale ◽  
Mechanical Resistance ◽  
Wind Flow ◽  
Horizontal Axis Wind Turbine ◽  
Immersive Environment

Virtual Reality (VR) is a rising technology that creates a computer-generated immersive environment to provide users a realistic experience, through which people who are not analysis experts become able to see numerical simulation results in a context that they can easily understand. VR supports a safe and productive working environment in which users can perceive worlds, which otherwise could be too complex, too dangerous, or impossible or impractical to explore directly, or even not yet in existence. In recent years, VR has been employed to an increasing number of scientific research areas across different disciplines, such as numerical simulation of Computational Fluid Dynamics (CFD) discussed in present study. Wind flow around wind turbines is a complex problem to simulate and understand. Predicting the interaction between wind and turbine blades is complicated by issues such as rotating motion, mechanical resistance from the breaking system, as well as inter-blade and inter-turbine wake effects. The present research uses CFD numerical simulation to predict the motion and wind flow around two types of turbines: 1) a small scale Vertical Axis Wind Turbine (VAWT) and 2) a small scale Horizontal Axis Wind Turbine (HAWT). Results from these simulations have been used to generate virtual reality (VR) visualizations and brought into an immersive environment to attempt to better understand the phenomena involved.

scholarly journals Investigasi Performa Turbin Angin Crossflow Dengan Simulasi Numerik 2D

2020 ◽  
Vol 8 (1) ◽  
pp. 7-12
Author(s):  
Diniar Mungil Kurniawati
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Slope Angle ◽  
Electrical Energy ◽  
Diameter Ratio ◽  
Cfd Modeling ◽  
Maximum Efficiency ◽  
Multiple Interactions

Wind turbine is a solution to harness of renewable energy because it requires wind as the main energy. Wind turbine work by extracting wind energy into electrical energy. Crossflow wind turbine is one of the wind turbines that are developed because it does not need wind direction to produce maximum efficiency. Crossflow wind turbines work with the concept of multiple interactions, namely in the first interaction the wind hits the first level of turbine blades, then the interaction of the two winds, the remainder of the first interaction enters the second level blades before leaving the wind turbine. In the design of crossflow wind turbine the diameter ratio and slope angle are important factors that influence to determine of performance in crossflow wind turbine. In this study varied the angle of slope 90 ° and variations in diameter ratio of 0.6 and 0.7. The study aimed to analyze the effect of diameter ratio and slope angle in performance of the crossflow wind turbine. This research was conducted with numerical simulation through 2D CFD modeling. The results showed that the best performance of crossflow wind turbine occurred at diameter ratio variation 0.7 in TSR 0.3 with the best CP value 0.34.

Nacelle Anemometry for the Electric Power Prediction System

2007 ◽  
Author(s):  
J. Kuroda ◽  
M. Iida ◽  
C. Arakawa
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Electric Power ◽  
Wind Velocity ◽  
Wind Turbines ◽  
Power Output ◽  
Measurement Data ◽  
Power Curve ◽  
Prediction System ◽  
Power Prediction

The purpose of this study is to establish the nacelle anemometry for the wind forecast. This paper describes the problems of the meteorological anemometry and the nacelle anemometry based on measurement data in Japan. In the results, it is shown that wind velocity measured at the mast is less related with power output of wind turbines than measured at the nacelle. However it seems power curve referred to the nacelle anemometer to shift to lower wind velocity. Then the numerical simulation is carried out for the flow field around the nacelle and the blade as the first step.

Wave Load Acting on Advanced Spar in Regular Waves

2018 ◽  
Author(s):  
Takayuki Hirai ◽  
Akira Sou ◽  
Yasunori Nihei
Keyword(s):  
Numerical Simulation ◽  
Wind Turbines ◽  
Wave Force ◽  
Offshore Wind ◽  
Column Diameter ◽  
Wave Load ◽  
Offshore Wind Turbines ◽  
The Difference ◽  
Floating Type ◽  
Good Agreement

Offshore wind turbines have been investigated and developed as one of the renewable energies. In Japan, the research and development of floating type offshore wind turbines have been carried out because the water around the country is too deep to settle the bottom mounted type. In this paper, we investigate the effects of the diameter of the column floater of the advanced spar in regular wave by using open source computational fluid dynamics software OpenFOAM. We use olaFOAM which equipped with the functions to set the boundary conditions of wave generation at the inlet and wave absorption at the outlet. The forces acting on a spar obtained by the numerical simulation and Morison’s equation are compared to examine the validity of the numerical model. A good agreement between them confirms the validity of the numerical method. Then we simulate numerically the effects of the column diameter on the flow around the advanced spars and the wave load. The result clarifies that Morison’s equation overestimates the wave force, and the difference increases with the column diameter. For more detailed analysis we divide the advanced spar into three parts, the upper spar above the column, the column floater and the lower spar below the column. As a result, we find that the difference between the wave load acting on the column by Morison’s equation and that by numerical simulation is dominant due to the flow separation around the column. Finally we modify the load coefficients of Morison’s equation for the column so that the modified equation can accurately evaluate the wave load acting on the advanced spar.

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