scholarly journals Aerodynamic Forces Affecting the H-Rotor Darrieus Wind Turbine

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Faris Alqurashi ◽  
M. H. Mohamed
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Aerodynamic Forces ◽  
Cross Sectional ◽  
Wind Potential ◽  
Horizontal Axis Wind Turbines ◽  
Darrieus Rotor ◽  
Static Conditions

Darrieus wind rotor is a vertical axis wind turbine that is a very promising kind of wind converters at remote and domestic locations that have soft and weak wind potential and speed, but from the quantitative comparison with horizontal axis wind turbines, this type of turbines has a weak performance. Additional researches are still needed to develop its efficiency to identify all the requirements of the generated power in low power demands. The aim of the current investigation is to analyze all the acting forces on the main parts of Darrieus rotor over the rotations as well as in maintenance and stationary conditions. Aerodynamic forces assessment will be executed for 3 different blade shapes (nonsymmetric and symmetric airfoils) like the airfoil section shapes of the Darrieus rotor blades. NACA 0021, LS413, and S1046 are selected as cross-sectional profile in this work. CFD simulations have been used in this work to get the different aerodynamic forces on the rotor blades of the Darrieus turbines. The present results indicated that the symmetric S1046 blade has higher forces during the rotation and stagnant (static) conditions. Moreover, the self-starting capability of NACA 0021 is better than S1046 due to low aerodynamic torsion on the S1046 blades.

scholarly journals Design and Simulation of Vertical Axis Wind Turbine with Naca 0021 Rotor Angle

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Dieniar N Ramadhani
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Fossil Fuels ◽  
Vertical Axis ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Energy Needs ◽  
Wind Potential ◽  
Wind Turbine Rotor

Much human energy needs are obtained from fossil fuels. This fossil energy is decreasing day by day. So that the utilization of natural energy such as solar energy, water energy and wind energy is being developed. Wind energy is energy that we can find, so it is very easy to use by using a turbine as the driving force. The vertical axis wind turbine is a type of wind turbine that is easier to apply in places where wind potential is not too large. This research was conducted by means of simulation using Qblade v0.963 software by comparing the influence generated from several numbers of wind turbine rotor blades. From the simulation process, it is known that the wind turbine rotor blades with 4 blades are the wind turbines capable of producing the greatest power, which is 75 Watts at a low TSR. So that in the manufacturing process it does not require large costs, but it still has to be built rigid and solidly.

Calculating the aerodynamics of vertical axis wind turbines

2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc
Keyword(s):  
Wind Turbine ◽  
Incidence Angle ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Velocity Triangle ◽  
Relationship Of ◽  
The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

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.

Vertical axis wind turbine operation in icing conditions: A review study

2021 ◽  
pp. 0309524X2110618
Author(s):  
Syed Abdur Rahman Tahir ◽  
Muhammad Shakeel Virk
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Electricity Production ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
Horizontal Axis Wind Turbines ◽  
Promising Solution ◽  
Review Study ◽  
Accretion Physics

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.

Investigation of aerodynamic forces and flow field of an H-type vertical axis wind turbine based on bionic airfoil

Energy ◽  
2021 ◽  
pp. 122999
Author(s):  
Yanfeng Zhang ◽  
Zhiping Guo ◽  
Xinyu Zhu ◽  
Yuan Li ◽  
Xiaowen Song ◽  
...  
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Aerodynamic Forces ◽  
Bionic Airfoil

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

2013 ◽  
Author(s):  
David Marten ◽  
Juliane Wendler ◽  
Georgios Pechlivanoglou ◽  
Christian Navid Nayeri ◽  
Christian Oliver Paschereit
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Turbine Rotor ◽  
Horizontal Axis ◽  
Vertical Axis Wind Turbine ◽  
First Case ◽  
Horizontal Axis Wind Turbines ◽  
Lift And Drag ◽  
The Impact

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.

The Straight-Bladed Morphing Vertical Axis Wind Turbine

2016 ◽  
Author(s):  
David MacPhee ◽  
Asfaw Beyene
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Low Cost ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Pitch Control ◽  
Control Schemes ◽  
Horizontal Axis Wind Turbines ◽  
Novel Concept

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.

Design and Analysis of the Aerodynamic Components for a Kilowatt Scale VAWT Optimized for Low Altitude Implementation in Remote Rural Villages

2011 ◽  
Author(s):  
Nathan E. Fuller ◽  
David M. Wiens ◽  
Allison L. Johnston ◽  
Jesse J. French
Keyword(s):  
Wind Turbine ◽  
Transmission Lines ◽  
Low Income ◽  
Vertical Axis ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Vertical Axis Wind Turbine ◽  
Rural Villages ◽  
Aerodynamic Properties ◽  
Horizontal Axis Wind Turbines

The ideal operating conditions for traditional horizontal axis wind turbines (HAWTs) are generally described by high velocity, steady winds, and undisturbed, laminar air flow. In the direct vicinity of populated areas, these conditions can only be achieved at altitudes significantly above or beyond the built-up area, typically twice the height of the tallest surrounding obstruction. The cost of tower material and transmission lines makes placing turbines at optimal operating heights cost-prohibitive in low-income, remote villages. Though not ideal for HAWT operation, the wind close to the earth’s surface and in proximity of residences can be utilized with an appropriately designed vertical axis wind turbine (VAWT). These turbines, while having a lower theoretical maximum efficiency, can survive and utilize the turbulent multidirectional winds in this operating region while still providing usable power. This paper highlights the design and analysis work performed by the authors to increase the aerodynamic efficiency of a unique and patented VAWT design in order to optimize it for implementation in remote rural villages. The final product is a kW capacity VAWT of unique geometry based on the previous successful testing of a 100W prototype. Specifically, the authors explored the aerodynamic effects of varying the geometry of the radial arms and center hubs of the turbine using CFD and wind tunnel testing. The design goal was to develop arms with aerodynamic properties that complemented the function of the blades at the appropriate phases of a single revolution. While the previous prototype focused mainly on minimizing drag, this effort sought to design an arm profile that develops high drag in one airflow direction and minimizes drag in the opposite direction. Implementation of these results was realized in a fully functioning drag VAWT. Furthermore, the system was designed to keep the turbine affordable for remote populations with limited resources. This data is compared to theoretical performance calculations, existing wind turbine designs, and against predictions made using scaling factors on preexisting data from the smaller prototype.

scholarly journals Design, Fabrication and Performance Evaluation of Hybrid Vertical Axis Wind Turbine

2020 ◽  
Vol 6 (6) ◽  
pp. 80-86
Author(s):  
Gwani Mohammed ◽  
Mamuda Buhari ◽  
Umar Muhammed Kangiwa ◽  
John Danyaro
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Substantial Improvement ◽  
Vertical Axis Wind Turbine ◽  
Experimental Conditions ◽  
Savonius Rotor ◽  
Darrieus Rotor ◽  
Low Efficiency ◽  
And Performance

Vertical axis wind turbines (VAWT) have attracted a lot of attention recently as an efficient tool in harnessing wind energy; however these types of wind turbine are faced with some challenges which affect their overall performance. The Darrieus rotor has difficulty to self-start by itself while the Savonius rotor has low efficiency. The performance of these turbines can be improved by combining the two VAWTs as one system. This paper presents the design of a hybrid VAWTs turbine. The Hybrid VAWTs combines the Darrieus rotor and the Savonius rotor as a single system to produce a high starting torque and enhanced efficiency. The Savonius rotor is placed at the centre of the three vertical blades of the Darrieus H-rotor to form the hybrid VAWTs. The hybrid VAWT was tested at four different wind speed i.e. V = 4.80 m/s, 4.50 m/s, 4.30 m/s and 3.90 m/s respectively. The performance of the hybrid VAWT was compared with the conventional straight bladed VAWT under similar experimental conditions. The obtained results showed that there is substantial improvement in the self-starting ability and coefficient of power (Cp). At V = 4.80 m/s, the Cp values for hybrid VAWT increased by 92% compared to straight bladed H-rotor VAWT. Similar improvement was also observed at wind speed of V = 4.50 m/s, 4.30 m/s, and 3.90 m/s where the Cp values increases by 71%, 10%, and 67% respectively compared to the straight bladed H-rotor.

scholarly journals Experimental Study of Vertical Axis Wind Turbine Performance under Vibration

2021 ◽  
Vol 1 (2) ◽  
pp. 177-185
Author(s):  
Md Rasel Sarkar ◽  
Sabariah Julai ◽  
Mst Jesmin Nahar ◽  
Moslem Uddin ◽  
Mahmudur Rahman ◽  
...  
Keyword(s):  
Power Generation ◽  
Experimental Study ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Dynamic Characteristics ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Flow Uniformity ◽  
Aerodynamic Forces ◽  
Turbine Performance

An experimental study was conducted to study the effects of flow uniformity on vibration and power generation of a small vertical axis wind turbine (VAWT). Previous studies have confirmed that one of the sources of vibration in the turbine is due to aerodynamic forces, which are due to incident wind. Firstly, understanding vibration is essential before proceeding to the measurements. In this experiment, further understand the vibrations of the turbine in operation, the operating deflection shape (ODS) technique was used. A wind tunnel and flow conditioner were fabricated. Experimental modal analysis (EMA) was conducted, and the dynamic characteristics are gathered. The ODS was conducted for operating the turbine at different speeds, with and without the flow conditioner. Results from EMA and ODS are correlated to explain the behavior of structures. In conclusion, the flow conditioner tested did have a big impact on the response of the structure in terms of vibration up to 30% indifference, but not so much in power generated about 2% indifference.

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