Investigation on Flow Characteristics and Performance of a Vertical Axis Wind Turbine With Deflector Plates

Author(s):  
K. Karthik Selva Kumar ◽  
Vinayak Kulkarni ◽  
Niranjan Sahoo

Abstract In this article, a 3D computational study has been performed to understand the flow phenomenon over the vertical axis wind turbine with a three-bladed NACA0021. The rotary motion of the VAWT simulated with sliding mesh techniques with reference to the SST-Kω turbulence model using the CFD software. The observed results were found to be having a significant improvement in the enhancement of the power output. Also, the investigation was move forwarded to understand the flow characteristics of the VAWT with the presence of deflector plates in different orientation at the upstream conditions. The present of deflector plates creates an augmented flow phenomenon which creates an accelerated flow at the near wake region, causing a significant improvement in the coefficient of power of the wind turbine.

2012 ◽  
Vol 499 ◽  
pp. 259-264
Author(s):  
Qi Yao ◽  
Ying Xue Yao ◽  
Liang Zhou ◽  
S.Y. Zheng

This paper presents a simulation study of an H-type vertical axis wind turbine. Two dimensional CFD model using sliding mesh technique was generated to help understand aerodynamics performance of this wind turbine. The effect of the pith angle on H-type vertical axis wind turbine was studied based on the computational model. As a result, this wind turbine could get the maximum power coefficient when pitch angle adjusted to a suited angle, furthermore, the effects of pitch angle and azimuth angle on single blade were investigated. The results will provide theoretical supports on study of variable pitch of wind turbine.


Vertical axis wind turbines are most effective for home energy generation especially in urban environments. Wind energy creates a stand-alone energy source that is relied on any place. The main criteria for this work is the design of micro wind turbines for all kinds of applications. Design of Twisted Blade Micro-Wind Turbine system is accomplished using computer aided design with Computational Fluid Dynamics (CFD). The flow characteristics in the wind turbine blade were analyzed by varying its twist ratio. The wind turbines with vertical axis utilize the wind from any direction with no yaw mechanism. The risk of blade ejection besides catching wind from all the directions is avoided by using the helical tye vertical axis wind turbine.


2012 ◽  
Vol 49 ◽  
pp. 254-262 ◽  
Author(s):  
Abdulkadir Ali ◽  
Steve Golde ◽  
Firoz Alam ◽  
Hazim Moria

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):  
N. Cristobal Uzarraga-Rodriguez ◽  
A. Gallegos-Mun˜oz ◽  
J. Manuel Riesco A´vila

A numerical analysis of a rooftop vertical axis wind turbine (VAWT) for applications in urban area is presented. The numerical simulations were developed to study the flow field through the turbine rotor to analyze the aerodynamic performance characteristics of the device. Three different blade numbers of wind turbine are studied, 2, 3 and 4, respectively. Each one of the models was built in a 3D computational model. The effects generated in the performance of turbines by the numbers of blades are considered. A Sliding Mesh Model (SMM) capability was used to present the dimensionless form of coefficient power and coefficient moment of the wind turbine as a function of the wind velocity and the rotor rotational speed. The numerical study was developed in CFD using FLUENT®. The results show the aerodynamic performance for each configuration of wind turbine rotor. In the cases of Rooftop rotor the power coefficient increases as the blade number increases, while in the case of Savonius rotor the power coefficient decrease as the blades number increases.


2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Vincenzo Dossena ◽  
Giacomo Persico ◽  
Berardo Paradiso ◽  
Lorenzo Battisti ◽  
Sergio Dell'Anna ◽  
...  

This paper presents the results of a wide experimental study on an H-type vertical axis wind turbine (VAWT) carried out at the Politecnico di Milano. The experiments were carried out in a large-scale wind tunnel, where wind turbines for microgeneration can be tested in real-scale conditions. Integral torque and thrust measurements were performed, as well as detailed aerodynamic measurements to characterize the flow field generated by the turbine downstream of the rotor. The machine was tested in both a confined (closed chamber) and unconfined (open chamber) environment, to highlight the effect of wind tunnel blockage on the aerodynamics and performance of the VAWT under investigation. The experimental results, compared with the blockage correlations presently available, suggest that specific correction models should be developed for VAWTs. The experimental thrust and power curves of the turbine, derived from integral measurements, exhibit the expected trends with a peak power coefficient of about 0.28 at tip-speed ratio equal to 2.5. Flow measurements, performed in three conditions for tip speed ratio equal to 1.5, 2.5, and 3.5, show the fully three-dimensional character of the wake, especially in the tip region where a nonsymmetrical wake and tip vortex are found. The unsteady evolution of the velocity and turbulence fields further highlights the effect of aerodynamic loading on the wake unsteadiness, showing the time-dependent nature of the tip vortex and the onset of dynamic stall for tip speed ratio lower than 2.


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