Development and Application of a Simulation Tool for Vertical and Horizontal Axis Wind Turbines

Author(s):  
David Marten ◽  
Juliane Wendler ◽  
Georgios Pechlivanoglou ◽  
Christian Navid Nayeri ◽  
Christian Oliver Paschereit

A double-multiple-streamtube vertical axis wind turbine simulation and design module has been integrated within the open-source wind turbine simulator QBlade. QBlade also contains the XFOIL airfoil analysis functionalities, which makes the software a single tool that comprises all functionality needed for the design and simulation of vertical or horizontal axis wind turbines. The functionality includes two dimensional airfoil design and analysis, lift and drag polar extrapolation, rotor blade design and wind turbine performance simulation. The QBlade software also inherits a generator module, pitch and rotational speed controllers, geometry export functionality and the simulation of rotor characteristics maps. Besides that, QBlade serves as a tool to compare different blade designs and their performance and to thoroughly investigate the distribution of all relevant variables along the rotor in an included post processor. The benefits of this code will be illustrated with two different case studies. The first case deals with the effect of stall delaying vortex generators on a vertical axis wind turbine rotor. The second case outlines the impact of helical blades and blade number on the time varying loads of a vertical axis wind turbine.

2021 ◽  
pp. 0309524X2110618
Author(s):  
Syed Abdur Rahman Tahir ◽  
Muhammad Shakeel Virk

Vertical Axis Wind Turbine (VAWT) can be a promising solution for electricity production in remote ice prone territories of high north, where good wind resources are available, but icing is a challenge that can affect its optimum operation. A lot of research has been made to study the icing effects on the conventional horizontal axis wind turbines, but the literature about vertical axis wind turbines operating in icing conditions is still scarce, despite the importance of this topic. This paper presents a review study about existing knowledge of VAWT operation in icing condition. Focus has been made in better understanding of ice accretion physics along VAWT blades and methods to detect and mitigate icing effects.


2018 ◽  
Vol 7 (4.13) ◽  
pp. 74 ◽  
Author(s):  
Muhd Khudri Johari ◽  
Muhammad Azim A Jalil ◽  
Mohammad Faizal Mohd Shariff

As the demand for green technology is rising rapidly worldwide, it is important that Malaysian researchers take advantage of Malaysia’s windy climates and areas to initiate more power generation projects using wind. The main objectives of this study are to build a functional wind turbine and to compare the performance of two types of design for wind turbine under different speeds and behaviours of the wind. A three-blade horizontal axis wind turbine (HAWT) and a Darrieus-type vertical axis wind turbine (VAWT) have been designed with CATIA software and constructed using a 3D-printing method. Both wind turbines have undergone series of tests before the voltage and current output from the wind turbines are collected. The result of the test is used to compare the performance of both wind turbines that will imply which design has the best efficiency and performance for Malaysia’s tropical climate. While HAWT can generate higher voltage (up to 8.99 V at one point), it decreases back to 0 V when the wind angle changes. VAWT, however, can generate lower voltage (1.4 V) but changes in the wind angle does not affect its voltage output at all. The analysis has proven that VAWT is significantly more efficient to be built and utilized for Malaysia’s tropical and windy climates. This is also an initiative project to gauge the possibility of building wind turbines, which could be built on the extensive and windy areas surrounding Malaysian airports.  


Author(s):  
David MacPhee ◽  
Asfaw Beyene

Blade pitch control has been extremely important for the development of Horizontal-Axis Wind Turbines (HAWTs), allowing for greater efficiency over a wider range of operational regimes when compared to rigid-bladed designs. For Vertical-Axis Wind Turbines (VAWTs), blade pitching is inherently more difficult due to a dependence of attack angle on turbine armature location, shaft speed, and wind speed. As a result, there have been very few practical pitch control schemes put forward for VAWTs, which may be a major reason why this wind turbine type enjoys a much lower market share as compared to HAWTs. To alleviate this issue, the flexible, straight-bladed vertical-axis turbine is presented, which can passively adapt its geometry to local aerodynamic loadings and serves as a low-cost blade pitch control strategy increasing efficiency and startup capabilities. Using two-dimensional fluid-structure action simulations, this novel concept is compared to an identical rigid one and is proven to be superior in terms of power coefficient due to decreased torque minima. Moreover, due to the flexible nature of the blades, the morphing turbine achieves less severe oscillatory loadings. As a result, the morphing blade design is expected to not only increase efficiency but also system longevity without additional system costs usually associated with active pitch control schemes.


Author(s):  
Hadi Sutanto ◽  
Chin-Tu Lu ◽  
Hodik Chaiyadi

The vertical-axis wind turbine has an advantage over the horizontal-axis wind turbine because of its structural simplicity due to the independence of motion in wind direction. This article describes a new idea on how to develop the Darrieus vertical-axis wind turbine by modifying the angle of attack and adding airfoils on the wind turbine. The wind turbine has a symmetrical airfoil of NACA 0012 with three-double blade configurations to optimize the performance of the vertical shaft wind turbine. A computational fluid dynamics technique was used to understand the impact of variations of wind velocity on the angle of attack and additional distance of airfoil in turbulence intensity based on the contour of wind velocity passing the wind turbine. Using this method, the authors showed that the results of the study in turn with the variation of wind velocity, different angle of attack and additional distance of airfoil have an effect on the values of lift and drag coefficient. The highest value of the coefficient of lift is 4.1, followed by the coefficient of drag which is 0.79 at 0.3 m with the angle of attack at -4o, the wind velocity is 9.428 m/s and the result of the highest torque is 0.57 Nm which has a coefficient of performance of 1.3%.


In the context of worldwide energetic transition, wind energy shows up as one of the most prominent renewable energy to provide an alternative for the conventional energy source. Therefore, new technologies of a wind turbine are developed, horizontal axis wind turbines have been extensively investigated and evolved. However, the development of vertical axis wind turbines is still an open and area of research, The main objective is to develop a more efficient type of wind turbines able to operate at low wind speeds to take hold maximum wind potential, The Savonius rotor goes with such conditions, however, it faces critical drawbacks, in particular, the low performance in comparison with horizontal axis wind turbines, as well, the blade in return of savonius wind turbine generates a negative torque leading to a decrement of turbine performance. The present work aims to investigate a modified model of the conventional Savonius rotors with a focus on improving the coefficient of power, transient computational fluid dynamics (CFD) simulations are carried out in an effort to perform a validation of numerical results according to experimental data, also to conduct a comparative analysis of both savonius models


2005 ◽  
Vol 29 (5) ◽  
pp. 449-461 ◽  
Author(s):  
Sandra Eriksson ◽  
H. Bernhoff

Torsional vibrations may be a critical issue for those vertical axis wind turbines having long drive trains as compared with standard horizontal axis wind turbines. Such vibrations are studied by simulation for two different types of generators used with a vertical axis wind turbine, namely a conventional induction generator with a gearbox and a directly-driven multipole synchronous generator. The synchronous generator has been designed with FEM simulations. The didactic calculations show from first principles that a directly-driven generator is to be preferred when torsional vibrations are considered, since the eigenfrequency of the fundamental vibration is greater for a directly driven generator than otherwise. Thus, the risk of resonance is reduced in a stiff assembly. The generator damping of the vibrations for the simulated, directly-driven synchronous generator is also studied.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6281
Author(s):  
Jia Guo ◽  
Liping Lei

Currently, vertical axis wind turbines (VAWT) are considered as an alternative technology to horizontal axis wind turbines in specific wind conditions, such as offshore farms. However, complex unsteady wake structures of VAWTs exert a significant influence on performance of wind turbines and wind farms. In the present study, instantaneous flow fields around and downstream of an innovative VAWT with inclined pitch axes are simulated by an actuator line model. Unsteady flow characteristics around the wind turbine with variations of azimuthal angles are discussed. Several fluid parameters are then evaluated on horizontal and vertical planes under conditions of various fold angles and incline angles. Results show that the total estimated wind energy in the shadow of the wind turbine with an incline angle of 30° and 150° is 4.6% higher than that with an incline angle of 90°. In this way, appropriate arrangements of wind turbines with various incline angles have the potential to obtain more power output in a wind farm.


2021 ◽  
Author(s):  
Anirudh P ◽  
Ratna Kishore Velamati ◽  
Srinath K S ◽  
Unnikrishnan D

Abstract The demand for wind turbines has increased ever since fossil fuels showed signs of quick depletion. Among wind turbines, Vertical Axis Wind Turbine (VAWT) is compact, produces less noise, is omnidirectional, resilient to turbulent flow, and is easy to maintain. The power generated by a VAWT is a function of a non-dimensional geometric parameter known as solidity (s), which is a function of turbine diameter (D), blade chord (c) and the number of blades (n). The present work analyses the impact of solidity (0.12 and 0.18) as a complete non-dimensional parameter on wind turbine performance. Each parameter of solidity is varied, keeping any one of the parameters constant and numerically studied for its performance across a range of tip speed ratios (TSR). For each solidity, six different combinations of VAWT geometric parameters were analyzed. In all the cases, the chord Reynolds number is kept constant. CFD simulation was performed on the Darrieus H-type (NACA0018 airfoil) VAWT. Two dimensional (2D) computational domains are used to study the effect on the turbine’s performance as the solidity studied is less than 0.4. Unsteady Reynolds-Averaged Navier-strokes (URANS) equation is used to solve the CFD model using ANSYS Fluent 19.1 with 4-equation transition SST k-ω for turbulence modelling. The comprehensive study of the turbine performance keeping the turbine operation within a constant Re number range shows the Coefficient of Performance (Cp) overlaps for a given solidity.


Author(s):  
Luai M. Al-Hadhrami ◽  
Shafiqur Rehman

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.


2014 ◽  
Vol 695 ◽  
pp. 801-805 ◽  
Author(s):  
Azizul Mohamad ◽  
Nasrul Amri Mohd Amin ◽  
Hong Tee Toh ◽  
Mohd Shukry Abdul Majid ◽  
Ruslizam Daud

Wind turbine is a device used to convert kinetic energy into electrical energy. Generally, wind turbine could be classified as horizontal axis and vertical axis wind turbine, depending on its axis of rotation. Two major factors affecting wind turbine performance are wind speed and aerodynamic design. While wind speed is depending on the location and weather, aerodynamic design of the wind turbine could be improved and optimized to enhance the wind turbine efficiency. This paper summarized few such design with particular attention on output power analysis as well as analysis tools development, for both type of wind turbine.


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