Design of Large-Scale, High-Efficient, Vertical Wind Turbine

2007 ◽  
Author(s):  
S. Lee ◽  
W.-S. Song ◽  
H.-R. Kim ◽  
J.-G. Park
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Roller Bearing ◽  
Maximum Power ◽  
Structural Safety ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Speed Ratio ◽  
Guide Vanes ◽  
High Efficient

This paper presents the overall design of a 2 MW vertical-type wind turbine power generation system. Firstly, the performance of the jet-wheel turbo turbine was optimized by considering the design parameters such as the rotor inlet angle, the solidity, and the diameter-height ratio with the guide vanes fixed. The effects of the side guide vane and the opening area ratio upon the efficiency were tested. As the wind speed increases from 3m/s to 7m/s, the maximum power coefficient reached the limit value of about 0.6 based on the rotor area, which is much higher than those of ever-designed three-bladed horizontal turbines. The maximum power coefficients occurred at the tip speed ratio ranging between 0.6 and 0.7. Based on the performance of small prototype model, the large-scale wind turbine rotor was designed within the constraints of material cost, machining cost, structural safety at extreme conditions, and maintenance. Thus, the aspect ratio of the diameter-to-height and the hub-tip ratio were set as 0.8 and 0.0857, respectively. All sides of the rotor were almost opened to achieve a maximum efficiency with only possible blocking by the sprocket gear attached to the bottom of the rotor. To evaluate the structural safety of the turbine at extreme wind speeds over 25m/s lasting 10 minutes, the numerical simulations were performed to evaluate the pressure loadings on the blades and the guide vanes. According to the structural analysis based on the pressure loadings and its weight, the entire system is considered to be stable for the extreme and static loadings. The overall performance of the jet-wheel turbo wind-turbine system was analyzed to find the capacity factor for the wind characteristics of Gillim province in China by considering the gear box efficiency, the roller bearing losses, and the SCIG/DFIG generator efficiency.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

Experimental Study of Vertical Axis Wind Turbine with Wind Speed Self-Adapting

2012 ◽  
Vol 215-216 ◽  
pp. 1323-1326
Author(s):  
Ming Wei Xu ◽  
Jian Jun Qu ◽  
Han Zhang
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Wind Velocity ◽  
Vertical Axis ◽  
Maximum Power ◽  
The Self ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Opening And Closing

A small vertical axis wind turbine with wind speed self-adapting was designed. The diameter and height of the turbine were both 0.7m. It featured that the blades were composed of movable and fixed blades, and the opening and closing of the movable blades realized the wind speed self-adapting. Aerodynamic performance of this new kind turbine was tested in a simple wind tunnel. Then the self-starting and power coefficient of the turbine were studied. The turbine with load could reliably self-start and operate stably even when the wind velocity was only 3.6 m/s. When the wind velocity was 8 m/s and the load torque was 0.1Nm, the movable blades no longer opened and the wind turbine realized the conversion from drag mode to lift mode. With the increase of wind speed, the maximum power coefficient of the turbine also improves gradually. Under 8 m/s wind speed, the maximum power coefficient of the turbine reaches to 12.26%. The experimental results showed that the new turbine not only improved the self-starting ability of the lift-style turbine, but also had a higher power coefficient in low tip speed ratio.

Virtual Prototype Modeling and Dynamics Analysis of a Large-Scale Wind Turbine’s Gearbox

2011 ◽  
Vol 314-316 ◽  
pp. 1043-1047
Author(s):  
Guo Yu Hu ◽  
Wen Lei Sun
Keyword(s):  
Optimal Design ◽  
Angular Velocity ◽  
Wind Turbine ◽  
Large Scale ◽  
Virtual Prototype ◽  
Design Parameters ◽  
Prototype Model ◽  
Flexible Body ◽  
Dynamics Analysis ◽  
Simulation Results

With the gearbox of a large-scale wind turbine as a study object, the virtual prototype model of gearbox is created based on UG and ADAMS softwares according to its design parameters such as structure and size. By rigid and flexible dynamics analysis for gearbox, the angular velocity and acceleration curves of the in-out shaft are obtained. Gear meshing forces and flexible body stress cloud using ADAMS are also obtained. It is verified that these results are coincided with the theoretical value through analysis and the simulation results of ADAMS are valid. The simulation results show that the design level of wind turbine gearboxes can be improved using the virtual prototype technology and lay a good foundation for further optimal design.

scholarly journals Numerical Analysis of Design Parameters With Strong Influence on the Aerodynamic Efficiency of a Small-Scale Self-Pitch VAWT

2015 ◽  
Author(s):  
Carlos Xisto ◽  
José Páscoa ◽  
Michele Trancossi
Keyword(s):  
Wind Turbine ◽  
Strong Influence ◽  
Vertical Axis ◽  
Periodic Variation ◽  
Numerical Approach ◽  
Design Parameters ◽  
Speed Ratio ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Four Bar Linkage

In the paper, four key design parameters with a strong influence on the performance of a small-scale high solidity variable pitch VAWT (Vertical Axis Wind Turbine), operating at low tip-speed-ratio (TSR) are addressed. To this aim a numerical approach, based on a finite-volume discretization of two-dimensional Unsteady RANS equations on a multiple sliding mesh, is proposed and validated against experimental data. The self-pitch VAWT design is based on a straight blade Darrieus wind turbine with blades that are allowed to pitch around a feathering axis, which is also parallel to the axis of rotation. The pitch angle amplitude and periodic variation are dynamically controlled by a four-bar-linkage system. We only consider the efficiency at low and intermediate TSR, therefore the pitch amplitude is chosen to be a sinusoidal function with a considerable amplitude. The results of this parametric analysis will contribute to define the guidelines for building a full size prototype of a small scale turbine of increased efficiency.

Study on Performance and Flow Condition of a Cross-Flow Wind Turbine With a Symmetrical Casing

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Junichiro Fukutomi ◽  
Toru Shigemitsu ◽  
Hiroki Daito
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Flow Condition ◽  
Cross Flow ◽  
Low Noise ◽  
Maximum Power ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
The Cross

A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10%) as compared to that of other small wind turbines. Prevailing winds in two directions often blow in urban and coastal regions. Therefore, in order to improve the performance and the flow condition of the cross-flow rotor, a casing suitable for this sort of prevailing wind conditions is designed in this research and the effect of the casing is investigated by experimental and numerical analysis. In the experiment, a wind tunnel with a square discharge is used and main flow velocity is set as 20 m/s. A torque meter, a rotational speed pickup, and a motor are assembled with the same axis as the test wind turbine and the tip speed ratio is changeable by a rotational speed controller. The casing is set around the cross-flow rotor and flow distribution at the rotor inlet and the outlet is measured by a one-hole pitot tube. The maximum power coefficient is obtained as Cpmax = 0.19 with the casing, however Cpmax = 0.098 without the casing. It is clear that the inlet and the outlet flow condition is improved by the casing. In the present paper, in order to improve the performance of a cross-flow wind turbine, a symmetrical casing suitable for prevailing winds in two directions is proposed. Then, the performance and the internal flow condition of the cross-flow wind turbine with the casing are clarified. Furthermore, the influence of the symmetrical casing on performance is discussed and the relation between the flow condition and performance is considered.

Research on Capture the Maximum Wind Energy Base on Fuzzy PID Controller

2012 ◽  
Vol 268-270 ◽  
pp. 1422-1425 ◽  
Author(s):  
Ying Ming Liu ◽  
En Yong Yi ◽  
Xiao Dong Wang ◽  
Hong Fang Xie
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Reactive Power ◽  
Maximum Power ◽  
Speed Ratio ◽  
Energy Capture ◽  
Maximum Wind ◽  
Fuzzy Pid Controller ◽  
Doubly Fed ◽  
Random Fluctuations

Abstract:This paper studies the control strategy of doubly-fed wind turbine to capture the maximum wind energy.The maximum wind energy capture is a more important part of the wind generation. Due to random fluctuations of the wind speed, to track the maximum power of wind turbine,we need to constantly adjust the speed of the generator, so that the generation run in the optimal tip speed ratio in different wind conditions,in order to achieve maximum power tracking. In this paper, the stator output indirect control the generator speed to achieve maximum wind energy capture,and decoupling control of active power and reactive power can be achieved.the MATLAB / SIMULINK simulation results verify the correctness and feasibility of this method.

Aerodynamic Performance Analysis of a Large Scale Wind Turbine Blade under Variable Condition

2013 ◽  
Vol 291-294 ◽  
pp. 527-530
Author(s):  
Peng Zhan Zhou ◽  
Fang Sheng Tan
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Wind Power ◽  
Turbine Blade ◽  
Large Scale ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
Variable Condition

Based on BLADED software, the aerodynamic performance of a large scale wind turbine blade was analyzed under variable condition. The results show that the rated power of the blade under variable condition is increased 10%, when the rated wind speed is changed from 10.5m/s to 11.0 m/s. The blade’s wind power coefficient is above 0.46, and its tip speed ratio is between 7.8 and 11.4. When its tip speed ratio is 9.5, the blade’s maximum wind power coefficient is 0.486. It is indicated that the blade has good aerodynamic performance and wide scope of wind speed adaptive capacity. The blade root’s equivalent fatigue load is 2.11 MN•m, and its extreme flapwise load is 4.61 MN•m. The loads under variable condition are both less than that of the designed condition, so the blade’s application under variable condition is safe.

Design of a Controllable One-Meter Scale Research Wind Turbine

2017 ◽  
Author(s):  
Samuel Cole ◽  
Gavin Hess ◽  
Martin Wosnik
Keyword(s):  
Reynolds Number ◽  
Wind Turbine ◽  
Reynolds Numbers ◽  
Low Flow ◽  
Design Parameters ◽  
Speed Ratio ◽  
Flow Physics ◽  
Manual Adjustment ◽  
High Reynolds ◽  
Turbine Design

A research wind turbine of one meter diameter was designed for the UNH Flow Physics Facility (FPF), a very large flow physics quality turbulent boundary layer wind tunnel (W 6m, H 2.7m, L 72m), which provides excellent spatial and temporal resolution, low flow blockage and allows measurements of turbine wakes far downstream due its long fetch. The initial turbine design was carried out as an aero-servo model of the NREL 5MW reference turbine, with subsequent modifications to both the hub to accommodate blade mounting and pitch-adjustment, and increases in model blade chord to achieve sufficiently high Reynolds numbers. A trade-off study of turbine design parameters in scale space was conducted. Several candidate airfoil profiles were evaluated numerically with the goal to reach Reynolds-number independence in turbine performance in the target operating range. The model turbine will achieve Reynolds numbers based on blade chord, an important consideration for airfoil performance and near-wake evolution, greater than 100,000, and Reynolds numbers based on turbine diameter, important for far-wake transport, on the order of 1,000,000. The blockage ratio is less than 5% based on swept area. A motor and controller combination was implemented that allows to precisely prescribe the turbine tip-speed ratio (at maximum power coefficient for optimum blade chord), which can remain stable and absorb the generated electric power for long periods of time. The turbine nacelle was designed with a blade mounting mechanism which allows for precise manual adjustment of blade pitch angle, while allowing for future implementation of actuated pitch control. The O(1m) turbine scale is viewed as a cost-effective compromise between size, driven by the need for sufficiently high Reynolds number, and the need for detailed measurements for significant distances downstream of the turbine under controlled conditions.

Optimization of Looped Airfoil Wind Turbine (LAWT™) Design Parameters for Maximum Power Generation

2016 ◽  
Author(s):  
Binhe Song ◽  
Subhodeep Banerjee ◽  
George Syrovy ◽  
Ramesh K. Agarwal
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Rural Areas ◽  
Analytical Formula ◽  
Maximum Power ◽  
Total Power ◽  
Design Parameters ◽  
Small Scale ◽  
Drag Coefficients ◽  
Lift And Drag

The looped airfoil wind turbine (LAWT™) is a patented new technology by EverLift Wind Tecnology, Inc. for generating power from wind. It takes advantage of the superior lift force of a linearly traveling wing compared to the rotating blades in conventional wind turbine configurations. Compared to horizontal and vertical axis wind turbines, the LAWT™ can be manufactured with minimal cost because it does not require complex gear systems and its blades have a constant profile along their length [1]. These considerations make the LAWT™ economically attractive for small-scale and decentralized power generation in rural areas. Each LAWT™ is estimated to generate power in the range of 10 kW to 1 MW. Due to various advantages, it is meaningful to determine the maximum power generation of a LAWT™ by optimizing the structural layout. In this study, CFD simulations were conducted using ANSYS Fluent to determine the total lift and drag coefficient for a cascade of airfoils. The k-kl-ω turbulence model was used to account for flow in the laminar-turbulent transition region. Given the lift and drag coefficients and the kinematics of the system, an analytical formula for the power generation of the LAWT™ was developed. General formulas were obtained for the average lift and drag coefficients so that the total power could be predicted for any number of airfoils in LAWT™. The spacing between airfoils was identified as the key design parameter that affected the power generation of the LAWT™. The results show that a marked increase in total power can be achieved if the optimum spacing between the airfoils is used.

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