scholarly journals Investigating of Flow Field and Power Performance on a Straight-blade Vertical Axis Wind Turbine with CFD Simulation

2021 ◽  
pp. 32-42
Author(s):  
Yanfeng Zhang ◽  
Zhiping Guo ◽  
Xiaowen Song ◽  
Xinyu Zhu ◽  
Chang Cai ◽  
...  
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Tangential Velocity ◽  
Vertical Axis ◽  
Blade Surface ◽  
Vertical Axis Wind Turbine ◽  
Power Performance ◽  
Freestream Velocity ◽  
Straight Blade

Forecasting the power performance and flow field of straight-blade vertical axis wind turbine (VAWT) and paying attention to the dynamic stall can enhance more adaptability to high turbulence and complicated wind conditions in cities environment. According to the blade element-momentum theory, the force of blade is analyzed in one period of revolution based on the structural characteristics of straight blade airfoil. The power performance of VAWT obtained by computational fluid dynamics (CFD) simulation is compared with experiment to estimate the accuracy about the numerical simulation results. As a result, the trend of average value of simulation Cpower is entirely consistent with the value of experiment data, and the extreme value of average Cpower of VAWT is 0.225 for tip speed ration (TSR) λ=2.19 when the freestream velocity is 8 m/s. The flow separation around the blade surface also gradually changes with the azimuth angle increasing, and the maximum pressure difference on the blade surface appears in the upstream. In the case of high leaf tip velocity, the synthetic velocity is much larger than the incoming wind velocity, and the angle of synthetic velocity increases slightly with the increase of blade tangential velocity. Thus, the angles of attack are very close in two TSRs λ=2.19 and 2.58. The research provides a computational model and theoretical basis for predicting wind turbine flow field to improve wind turbine power performance.

Wind Tunnel Test on Icing on a Straight Blade for Vertical Axis Wind Turbine

2011 ◽  
Vol 301-303 ◽  
pp. 1735-1739
Author(s):  
Yan Li ◽  
Fang Feng ◽  
Sheng Mao Li ◽  
Wen Qiang Tian ◽  
Kotaro Tagawa
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Force Balance ◽  
Blade Surface ◽  
Vertical Axis Wind Turbine ◽  
Straight Blade ◽  
Drag And Lift Coefficients ◽  
Ice Accretions ◽  
Drag And Lift

Icing on blade surface of the wind turbine set in cold regions is a serious problem. To invest the mechanism of icing and ice accretion on blade surface, wind tunnel tests were carried out on a static straight blade used for the straight-bladed vertical axis wind turbine by using an icing wind tunnel. The icing and ice accretions on blade surface at some typical angles of attack were observed and recorded in a fixed wind speed and steady flow discharge. The mass of ice accretions on the surface of blade were also measured and compared. At the same time, the drag and lift coefficients were tested by a three-component force balance. Based on the test results, the factors affecting the mass and characteristic of ice accretions and the drag and lift coefficients of the straight blade were discussed.

426 Research on the Flow Field around Low Tip Speed Ratio Type Straight Blade Vertical Axis Wind Turbine

2013 ◽  
Vol 2013.62 (0) ◽  
pp. 257-258
Author(s):  
Toshiaki KAWABATA ◽  
Takao MAEDA ◽  
Yasunari KAMADA ◽  
Junsuke MURATA ◽  
Qing'an LI
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Straight Blade ◽  
Tip Speed Ratio

CFD Sensitivity Analysis of a Straight-Blade Vertical Axis Wind Turbine

2012 ◽  
Vol 36 (5) ◽  
pp. 571-588 ◽  
Author(s):  
Khaled M Almohammadi ◽  
D B Ingham ◽  
L Ma ◽  
M Pourkashanian
Keyword(s):  
Aspect Ratio ◽  
Flow Field ◽  
Wind Turbine ◽  
Turbulence Intensity ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Computational Domain ◽  
Vertical Axis Wind Turbine ◽  
Airfoil Surface ◽  
Straight Blade

This paper investigates the flow field features and the predicted power coefficient of a straight blade vertical axis wind turbine (SB-VAWT) using computational fluid dynamics modeling using 2D simulations. The Unsteady Navier-Stokes equations are solved with the concept of Reynolds averaging using the commercial software FLUENT and the sliding mesh technique is applied. In the mesh phase, three parameters have been investigated, namely the cell type, the cell aspect ratio on the airfoil surface, and the total number of cells in the computational domain. In the simulation phase, two parameters have been investigated, namely the time step/Courant number, and the turbulence intensity. Significant differences have been observed in the flow field features and on the predicted power coefficient for some of these parameters which if not considered in details could lead to unreliable predictions. The sensitivity of the parameters is not equally significant and this paper suggests which parameters should be focused on in the modeling process. The convergence behavior of the quadrilateral based mesh is found to be more consistent compared to the triangular based mesh. In the mesh phase, the cell aspect ratio on the airfoil surface was found to be a significant factor, whereas the turbulence intensity was found to be a significant fac-tor in the simulation phase.

3-D CFD Modeling the Straight Blade Vertical Axis Wind Turbine

2013 ◽  
Vol 683 ◽  
pp. 653-656 ◽  
Author(s):  
Qiu Ping Yang ◽  
Roderick Galbraith ◽  
De Ke Xi
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Vertical Wind ◽  
Cfd Modeling ◽  
Vertical Axis Wind Turbine ◽  
Straight Blade ◽  
Fluent Software

This paper use the Fluent software to calculate the flow field of the vertical axis wind turbine. The results got were almost agreeable with the experimental data. The results were much better agreeable with the experimental data when the TSR was larger than 1 .So it can be used as the fast and lower costing estimated tools for the vertical wind turbines.

425 Research on the Blade Surface Pressure Distribution of Straight Blade Vertical Axis Wind Turbine

2013 ◽  
Vol 2013.62 (0) ◽  
pp. 255-256
Author(s):  
Qing'an LI ◽  
Takao MAEDA ◽  
Yasunari KAMADA ◽  
Junsuke MURATA ◽  
Toshiaki KAWABATA ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Pressure Distribution ◽  
Surface Pressure ◽  
Vertical Axis ◽  
Blade Surface ◽  
Vertical Axis Wind Turbine ◽  
Straight Blade ◽  
Surface Pressure Distribution

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.

Modeling dynamic stall of a straight blade vertical axis wind turbine

2015 ◽  
Vol 57 ◽  
pp. 144-158 ◽  
Author(s):  
K.M. Almohammadi ◽  
D.B. Ingham ◽  
L. Ma ◽  
M. Pourkashanian
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Dynamic Stall ◽  
Vertical Axis Wind Turbine ◽  
Straight Blade

scholarly journals Effect of Pitch Parameters on Aerodynamic Forces of a Straight-Bladed Vertical Axis Wind Turbine with Inclined Pitch Axes

2021 ◽  
Vol 11 (3) ◽  
pp. 1033
Author(s):  
Jia Guo ◽  
Timing Qu ◽  
Liping Lei
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Speed Ratio ◽  
Incline Angle ◽  
Asymmetric Distribution ◽  
Vertical Axis Wind Turbine ◽  
Power Performance ◽  
Aerodynamic Forces ◽  
Ansys Fluent ◽  
Pitch Regulation

Pitch regulation plays a significant role in improving power performance and achieving output control in wind turbines. The present study focuses on a novel, pitch-regulated vertical axis wind turbine (VAWT) with inclined pitch axes. The effect of two pitch parameters (the fold angle and the incline angle) on the instantaneous aerodynamic forces and overall performance of a straight-bladed VAWT under a tip-speed ratio of 4 is investigated using an actuator line model, achieved in ANSYS Fluent software and validated by previous experimental results. The results demonstrate that the fold angle has an apparent influence on the angles of attack and forces of the blades, as well as the power output of the wind turbine. It is helpful to further study the dynamic pitch regulation and adaptable passive pitch regulation of VAWTs. Incline angles away from 90° lead to the asymmetric distribution of aerodynamic forces along the blade span, which results in an expected reduction of loads on the main shaft and the tower of VAWTs.

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