Wind Direction Characteristics of a Vertical Axis Wind Turbine Using the Mechanism of a Bird’s Wing With a Wind Collector

Author(s):  
Yoshiaki Tanzawa ◽  
Takao Sato ◽  
Takumi Hashizume

This paper describes the wind direction characteristics of the wind collector used for our 8th model of the vertical axis wind turbine using the mechanism of a bird’s wing. The 8th model is divided into two sections top and bottom. Each section looks like a Savonius wind turbine. The blade is divided into seven rows of plates. Each 0.18mm stainless plate has only one side attached to the frame. Wind from the outside enlarges the space between the blades, and passes through. However, wind from the inside closes the space. In the wind collector, four wind collection boards are located every 90 degrees around this wind turbine. In an earlier paper, it was confirmed that these collection boards collected 1.6 times the wind and resulted in twice the output. In this paper, the variations in the wind collector characteristics due to the wind direction are clarified experimentally. A wind tunnel experiment using six different wind directions shows that the output increases for four wind directions and decreases for one wind direction. Additionally, the computer simulation confirms the wind direction and the wind speed distribution around the wind turbine when the wind collection boards are in place.

2009 ◽  
Vol 33 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Andrzej J. Fiedler ◽  
Stephen Tullis

A high solidity, small scale, 2.5m diameter by 3m high Vertical Axis Wind Turbine (VAWT) consisting of three NACA 0015 profile blades, each with a span of 3m and a chord length of 0.4m, was tested in an open-air wind tunnel facility to investigate the effects of preset toe-in and toe-out turbine blade pitch. The effect of blade mount-point offset was also investigated. The results from these tests are presented for a range of tip speed ratios, and compared with an extensive base data set obtained for a nominal wind speed of 10m/s. Results show measured performance decreases of up to 47% for toe-in, and increases of up to 29% for toe-out blade pitch angles, relative to the zero preset pitch case. Also, blade mount-point offset tests indicate decreases in performance as the mount location is moved from mid-chord towards the leading edge, as a result of an inherent toe-in condition. Observations indicate that these performance decreases may be minimized by compensating for the blade mount offset with a toe-out preset pitch. The trends of the preset blade pitch tests agree with those found in literature for much lower solidity turbines.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hashwini Lalchand Thadani ◽  
Fadia Dyni Zaaba ◽  
Muhammad Raimi Mohammad Shahrizal ◽  
Arjun Singh Jaj A. Jaspal Singh Jaj ◽  
Yun Ii Go

PurposeThis paper aims to design an optimum vertical axis wind turbine (VAWT) and assess its techno-economic performance for wind energy harvesting at high-speed railway in Malaysia.Design/methodology/approachThis project adopted AutoCAD and ANSYS modeling tools to design and optimize the blade of the turbine. The site selected has a railway of 30 km with six stops. The vertical turbines are placed 1 m apart from each other considering the optimum tip speed ratio. The power produced and net present value had been analyzed to evaluate its techno-economic viability.FindingsComputational fluid dynamics (CFD) analysis of National Advisory Committee for Aeronautics (NACA) 0020 blade has been carried out. For a turbine with wind speed of 50 m/s and swept area of 8 m2, the power generated is 245 kW. For eight trains that operate for 19 h/day with an interval of 30 min in nonpeak hours and 15 min in peak hours, total energy generated is 66 MWh/day. The average cost saved by the train stations is RM 16.7 mil/year with battery charging capacity of 12 h/day.Originality/valueWind energy harvesting is not commonly used in Malaysia due to its low wind speed ranging from 1.5 to 4.5 m/s. Conventional wind turbine requires a minimum cut-in wind speed of 11 m/s to overcome the inertia and starts generating power. Hence, this paper proposes an optimum design of VAWT to harvest an unconventional untapped wind sources from railway. The research finding complements the alternate energy harvesting technologies which can serve as reference for countries which experienced similar geographic constraints.


2012 ◽  
Vol 215-216 ◽  
pp. 1323-1326
Author(s):  
Ming Wei Xu ◽  
Jian Jun Qu ◽  
Han Zhang

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.


Author(s):  
Mohamed Saiful Firdaus Hussin ◽  
Mohd Fariduddin Mukhtar ◽  
Mohd Zaidi Mohd Tumari ◽  
Nursabillilah Mohd Ali ◽  
Amir Abdullah Muhammad Damanhuri ◽  
...  

KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 172
Author(s):  
Tedy Harsanto ◽  
Haryo Dwi Prananto ◽  
Esmar Budi ◽  
Hadi Nasbey

<p>A vertical axis wind turbine triple-stage savonius type has been created by using simple materials to generate electricity for the alternative wind power plant. The objective of this research is to design a simple wind turbine which can operate with low wind speed. The turbine was designed by making three savonius rotors and then varied the structure of angle on the three rotors, 0˚, 90˚ and 120˚. The dimension of the three rotors are created equal with each rotor diameter 35 cm and each rotor height 19 cm. The turbine was tested by using blower as the wind sources. Through the measurements obtained the comparisons of output power, rotation of turbine, and the level of efficiency generated by the three variations. The result showed that the turbine with angle of 120˚ operate most optimally because it is able to produce the highest output power and highest rotation of turbine which is 0.346 Watt and 222.7 RPM. </p><p><strong>Keywords</strong>: Output power; savonius turbine; triple-stage; the structure of angle</p>


Author(s):  
Dygku. Asmanissa Awg. Osman ◽  
Norzanah Rosmin ◽  
Nor Shahida Hasan ◽  
Baharruddin Ishak ◽  
Aede Hatib Mustaamal@Jamal ◽  
...  

The air streams from the outlet of an air compressor can be used to generate electricity. For instance, if a micro-sized Vertical-Axis Wind-Turbine (VAWT) is installed towards the airflow, some amount of electricity can be generated before being stored in a battery bank. The research’s objectives are to design, fabricate and analyze the performance of Helical Savonius VAWT blade rotors, which is tested with and without using a wind concentrator. The Helical Savonius VAWT is tested at 0 cm without the concentrator, whereas the blade rotor is tested at concave-blade position when using the concentrator. The blade and the wind concentrator designs were based on the dimensions and the constant airflow of the air compressor. The findings suggested that the blade produced its best performance when tested using wind concentrator at concave-blade position in terms of angular speed (<em>ω</em>), tip speed ratio (<em>TSR</em>) and the generated electrical power (<em>P</em><em><sub>E</sub></em>). The findings concluded that the addition of wind concentrator increases the airflow which then provided better performances on the blades.


2020 ◽  
Vol 188 ◽  
pp. 00017
Author(s):  
Khairunnisa Khairunnisa ◽  
Syaiful Rachman ◽  
Edi Yohanes ◽  
Awan Uji Krismanto ◽  
Jazuli Fadil ◽  
...  

Vertical axis wind turbine (VAWT) can be operated in any direction of wind speed, but it has low rotation. To improve the performance of VAWT in which low rotation, this paper presents a simple control strategy of VAWT using a DC-DC boost converter to tap constant voltage in a standalone application. The main objective of this research is to maintain a constant output voltage of converter despite variation input voltage affected by variable wind speed. A simple proportional-integral (PI) controller has been used for a DC-DC boost converter and tested in MATLAB-Simulink environment, with the closed-loop system of the converter maintain constant output voltage although the wind speed is kept changing. The PI controller obtains the feedback from the output voltage of the boost converter to produce the correct pulse width modulation (PWM) duty cycle and trigger the metal oxide semiconductor field effect transistor (MOSFET) following the reference voltage of the turbine. This system has suppressed the value of overshoot and increased the efficiency of wind turbines as 34 %.


Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1465 ◽  
Author(s):  
Andrés Meana-Fernández ◽  
Jesús Manuel Fernández Oro ◽  
Katia María Argüelles Díaz ◽  
Mónica Galdo-Vega ◽  
Sandra Velarde-Suárez

Wind tunnel testing of small-scale models is one of the most useful techniques to predict the performance of real-scale applications. In this work, the aerodynamic design and the construction of a small-scale model of a straight-bladed vertical axis wind turbine for wind tunnel testing has been performed. Using a double multiple streamtube model (DMST), different solidity values for the turbine and different airfoil geometries were compared to select the final design. Once an optimal design was selected, a numerical simulation using Computational Fluid Dynamics (CFD) was performed in order to obtain a more precise description of the flow field as well as the performance of the model. Future work will comprise the characterization of the model and the comparison of the experimental and numerical results.


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