CFD Modeling and Design of Wind Boosters for Low Speed Vertical Axis Wind Turbines

2014 ◽  
Vol 1016 ◽  
pp. 554-558 ◽  
Author(s):  
Natapol Korprasertsak ◽  
Nataporn Korprasertsak ◽  
Thananchai Leephakpreeda
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Cfd Modeling ◽  
Wind Flow ◽  
Average Wind Speed ◽  
Low Speed ◽  
Vertical Axis Wind Turbines ◽  
Average Wind ◽  
Computational Fluid Dynamics Cfd

In Thailand, the average wind speed is generally quite low (≈ 3 - 4 m/s). Although Vertical Axis Wind Turbines (VAWTs) are designed for low speed wind, standalone VAWTs are still unable to generate power satisfactorily under that practical condition. This study introduces a new design of a wind flow controlling device, called a “wind booster”, by utilizing Computational Fluid Dynamics (CFD). A wind booster is developed for incorporating with a VAWT in order to increase the performance of the VAWT and to overcome the limitation of harvesting energy with low availability at low speed wind. The guiding and throttling effects of the optimal design of the wind booster are able to increase the angular velocity of VAWTs which leads to an increase in power generated from VAWTs.

Investigation of Self-Starting Capability of Vertical Axis Wind Turbines Using a Computational Fluid Dynamics Approach

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Alexandrina Untaroiu ◽  
Houston G. Wood ◽  
Paul E. Allaire ◽  
Robert J. Ribando
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Mesh Deformation ◽  
Operating Speed ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
Turbine Performance

Vertical axis wind turbines have always been a controversial technology; claims regarding their benefits and drawbacks have been debated since the initial patent in 1931. Despite this contention, very little systematic vertical axis wind turbine research has been accomplished. Experimental assessments remain prohibitively expensive, while analytical analyses are limited by the complexity of the system. Numerical methods can address both concerns, but inadequate computing power hampered this field. Instead, approximating models were developed which provided some basis for study; but all these exhibited high error margins when compared with actual turbine performance data and were only useful in some operating regimes. Modern computers are capable of more accurate computational fluid dynamics analysis, but most research has focused on horizontal axis configurations or modeling of single blades rather than full geometries. In order to address this research gap, a systematic review of vertical axis wind-power turbine (VAWT) was undertaken, starting with establishment of a methodology for vertical axis wind turbine simulation that is presented in this paper. Replicating the experimental prototype, both 2D and 3D models of a three-bladed vertical axis wind turbine were generated. Full transient computational fluid dynamics (CFD) simulations using mesh deformation capability available in ansys-CFX were run from turbine start-up to operating speed and compared with the experimental data in order to validate the technique. A circular inner domain, containing the blades and the rotor, was allowed to undergo mesh deformation with a rotational velocity that varied with torque generated by the incoming wind. Results have demonstrated that a transient CFD simulation using a two-dimensional computational model can accurately predict vertical axis wind turbine operating speed within 12% error, with the caveat that intermediate turbine performance is not accurately captured.

scholarly journals Design Mining Interacting Wind Turbines

2016 ◽  
Vol 24 (1) ◽  
pp. 89-111 ◽  
Author(s):  
Richard J. Preen ◽  
Larry Bull
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Initial Study ◽  
3D Printer ◽  
Vertical Axis Wind Turbines ◽  
Training Samples ◽  
Computational Fluid Dynamics Simulations ◽  
Model Training ◽  
Dynamics Simulations

An initial study has recently been presented of surrogate-assisted evolutionary algorithms used to design vertical-axis wind turbines wherein candidate prototypes are evaluated under fan-generated wind conditions after being physically instantiated by a 3D printer. Unlike other approaches, such as computational fluid dynamics simulations, no mathematical formulations were used and no model assumptions were made. This paper extends that work by exploring alternative surrogate modelling and evolutionary techniques. The accuracy of various modelling algorithms used to estimate the fitness of evaluated individuals from the initial experiments is compared. The effect of temporally windowing surrogate model training samples is explored. A surrogate-assisted approach based on an enhanced local search is introduced; and alternative coevolution collaboration schemes are examined.

CFD modeling of varying complexity for aerodynamic analysis of H-vertical axis wind turbines

2020 ◽  
Vol 145 ◽  
pp. 2658-2670 ◽  
Author(s):  
Jiao He ◽  
Xin Jin ◽  
Shuangyi Xie ◽  
Le Cao ◽  
Yaming Wang ◽  
...  
Keyword(s):  
Wind Turbines ◽  
Vertical Axis ◽  
Cfd Modeling ◽  
Aerodynamic Analysis ◽  
Vertical Axis Wind Turbines

scholarly journals Application of Simultaneous Symmetric and Cambered Airfoils in Novel Vertical Axis Wind Turbines

2021 ◽  
Vol 11 (17) ◽  
pp. 8011
Author(s):  
Sajad Maleki Dastjerdi ◽  
Kobra Gharali ◽  
Armughan Al-Haq ◽  
Jatin Nathwani
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Dynamic Stall ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbines ◽  
Good Potential ◽  
Computational Fluid Dynamics Cfd ◽  
Naca0018 Airfoil

Two novel four-blade H-darrieus vertical axis wind turbines (VAWTs) have been proposed for enhancing self-start capability and power production. The two different airfoil types for the turbines are assessed: a cambered S815 airfoil and a symmetric NACA0018 airfoil. For the first novel wind turbine configuration, the Non-Similar Airfoils 1 (NSA-1), two NACA0018 airfoils, and two S815 airfoils are opposite to each other. For the second novel configuration (NSA-2), each of the S815 airfoils is opposite to one NACA0018 airfoil. Using computational fluid dynamics (CFD) simulations, static and dynamic conditions are evaluated to establish self-starting ability and the power coefficient, respectively. Dynamic stall investigation of each blade of the turbines shows that NACA0018 under dynamic stall impacts the turbine’s performance and the onset of dynamic stall decreases the power coefficient of the turbine significantly. The results show that NSA-2 followed by NSA-1 has good potential to improve the self-starting ability (13.3%) compared to the turbine with symmetric airfoils called HT-NACA0018. In terms of self-starting ability, NSA-2 not only can perform in about 66.67% of 360° similar to the wind turbine with non-symmetric airfoils (named HT-S815) but the power coefficient of NSA-2 at the design tip speed ratio of 2.5 is also 4.5 times more than the power coefficient of HT-S815; the power coefficient difference between HT-NACA0018 and HT-S815 (=0.231) is decreased significantly when HT-S815 is replaced by NSA-2 (=0.076). These novel wind turbines are also simple.

scholarly journals Numerical investigation of the effect of triangle strut in vertical axis wind turbine (VAWT)

2020 ◽  
Vol 11 (2) ◽  
pp. 95
Author(s):  
Tri Admono ◽  
Yoyon Ahmudiarto ◽  
Amma Muliya Romadoni ◽  
Iman Abdurahman ◽  
Agus Salim ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Simulation Method ◽  
Wind Flow ◽  
Vertical Axis Wind Turbine ◽  
Pressure Losses ◽  
Multi Stage ◽  
Computational Fluid Dynamics Cfd

Strut is used in vertical axis wind turbine (VAWT) to restraint the framework. In this study, struts are analyzed to show the pressure losses in VAWT. ANSYS computational fluid dynamics (CFD) software is used to investigate triangle strut in VAWT. This study aims to show a CFD simulation of struts, which affects the aerodynamic of VAWT. In CFD software, the aerodynamic of VAWT can be analyzed in terms of pressure losses in the struts. The simulation method starts by making a struts model, then meshing and setting up ANSYS's boundary conditions. The last iteration runs in ANSYS until convergence. Our results show the percentage of pressure losses with the variation of the angle of wind 0°, 20°, 40°, and 60° are 0.67 %, 0.52 %, 0.48 %, and 0.52 %. The effect of triangle strut in VAWT did not affect the wind flow to the VAWT blade. The results also indicated that the triangle strut could be applied in the multi-stage of VAWT system.

Wind Power Output Performance Horizontal and Vertical Axis Wind Turbines for Isolated Small Applications in Saudi Arabia

2014 ◽  
Author(s):  
Luai M. Al-Hadhrami ◽  
Shafiqur Rehman
Keyword(s):  
Wind Turbines ◽  
Vertical Axis ◽  
Horizontal Axis ◽  
Energy Output ◽  
Energy Yield ◽  
Vertical Axis Wind Turbine ◽  
Average Wind Speed ◽  
Maximum Increase ◽  
Vertical Axis Wind Turbines ◽  
Horizontal Axis Wind Turbines

The study evaluated the energy output and plant capacity factor of small wind turbines in the category of 3–10 kW rated power. The effects of hub height on energy output and the PCF have been studied. To achieve the set objectives, hourly average wind speed data measured at 10, 20, 30, and 40 meter and wind direction at 30 and 40 meter above ground level during July 01, 2006 to July 10, 2008 has been utilized. The highest percentage change in annual energy yield (AEY) was obtained for an increase in hub height from 20 to 30 m for both horizontal and vertical wind turbines used in this study. Horizontal axis wind turbines HAWT-1, HAWT-2, and HAWT-6; and vertical axis wind turbines VAWT-1, VAWT-2, and VAWT-4 are recommended for various ranges of loads. Horizontal axis wind turbines were found generally more efficient than the vertical axis wind turbine in the present case. In general, all the turbines showed a maximum increase in energy yield for an increase of 10 m in hub height from 20 to 30m and the annual mean energy yield usually followed the load pattern in the study area. Lastly, the mean turbulence intensity was always less than the value recommended in IEC64100-1 standard.

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