scholarly journals Analysis and implementation of a drag-type vertical-axis wind turbine for small distributed wind energy systems

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401982570 ◽  
Author(s):  
Zheng Li ◽  
Ruihua Han ◽  
Peifeng Gao ◽  
Caisheng Wang

This article investigates a drag-type vertical-axis wind turbine that is targeted for small-scale wind energy system applications. Based on aerodynamics models, the three-dimensional simulation studies have been carried out to obtain the force distributions along blades and eventually the torque and power coefficients for different vertical-axis wind turbine configurations. An optimal vertical-axis wind turbine configuration is chosen based on the comparative analysis, and a 2 kW prototype system has been implemented based on the design. The effectiveness of the three-dimensional models and simulation results has been verified by the measured data from the actual vertical-axis wind turbine system. The wake impacts to the vertical-axis wind turbine caused by nearby objects are also analyzed. The simulation results and the actual operation experiences show that the proposed system has the characteristics of low cut-in speed, high power density, and robustness to adjacent objects (such as buildings and other wind turbines), which make it suitable for small-scale wind energy systems in populated areas including urban environment.

2017 ◽  
Vol 85 ◽  
pp. 396-414 ◽  
Author(s):  
Imen Bel Mabrouk ◽  
Abdelkhalak El Hami ◽  
Lassâad Walha ◽  
Bacem Zghal ◽  
Mohamed Haddar

Energy ◽  
2017 ◽  
Vol 133 ◽  
pp. 179-190 ◽  
Author(s):  
Abhishek Subramanian ◽  
S. Arun Yogesh ◽  
Hrishikesh Sivanandan ◽  
Abhijit Giri ◽  
Madhavan Vasudevan ◽  
...  

2021 ◽  
Vol 926 (1) ◽  
pp. 012093
Author(s):  
Y Kassem ◽  
H Çamur ◽  
M A H A Abdalla ◽  
B D Erdem ◽  
A M R Al-ani

Abstract The grid-connected system can be an attractive solution to reduce electricity consumption, dependence on utility power, and increase electricity generation from renewable energy resources like wind energy for residential electricity users. Based on 33-year wind data (1983-2020), this study investigates the potential of wind energy at different locations ((Akkar, Baalbek, Beirut, Zahlé, Baabda, Nabatieh, Tripoli, and Sidon) in Lebanon using the Weibull distribution function. Monthly NASA wind speed data during the period (1983-2020) were used to estimate the wind energy potential. The result showed that the averaged wind speeds at the selected regions are varied from 3.695m/s to 4.457m/s at the height of 10m. Furthermore, the annual wind power density was estimated at various heights (10m, 30m, and 50m). The results demonstrated that small-scale wind turbines are recommended to be used for generating electricity from wind in the selected regions. Finally, the performance of WRE.060 / 6 kW (vertical axis wind turbine) and Proven WT 6000 (horizontal axis wind turbine) was done based on the monthly NASA wind speed database.


2012 ◽  
Vol 455-456 ◽  
pp. 334-338
Author(s):  
Yong Zhe Lv ◽  
Dong Xiang Jiang ◽  
Yong Jiang

This paper presents an analysis on the performance of vertical axis wind turbine of two types, namely straight-blade vertical axis wind turbine (SB-VAWT) and twisted-blade vertical axis wind turbine (TB-VAWT). An attempt of this simulation is to identify which type performs better in the same wind conditions and swept area. Three-dimensional computational fluid dynamics (CFD) was adopted in this analysis, after solid models of them were generated. Preliminary results of torque, power and aerodynamics in the fluid field were obtained for discussion. Finally, there provided some guidance for future wind tunnel tests.


Author(s):  
Jelena Svorcan ◽  
◽  
Ognjen Peković ◽  
Toni Ivanov ◽  
Miloš Vorkapić ◽  
...  

With wind energy extraction constantly increasing, the interest in small-scale urban wind turbines is also expanding. Given that these machines often work in adverse operating conditions (Earth’s boundary layer, vortex trails of surrounding objects, small and changeable wind speeds), additional elements that locally augment wind velocity and facilitate turbine start may be installed. This paper investigates possible benefits of adding an optimized flow concentrator to a vertical-axis wind turbine (VAWT) rotor. Three-dimensional, unsteady, turbulent, incompressible flow simulations of both isolated rotor consisting of three straight blades and a rotor with flow concentrator have been performed in ANSYS FLUENT by finite volume method for several different operational regimes. This type of flow simulations is challenging since flow angles are high, numerous flow phenomena and instabilities are present and the interaction between the blades and detached vortices can be significant. The rotational motion of the blades is solved by the unsteady Sliding Mesh (SM) approach. Flow field is modeled by Unsteady Reynolds Averaged Navier-Stokes (URANS) equations with k-ω SST turbulence model used for closure. Both quantitative and qualitative examinations of the obtained numerical results are presented. In particular, the two computed power coefficient curves are compared and the advantages of installing a flow concentrator are accentuated.


2020 ◽  
Vol 17 (2) ◽  
pp. 833-839
Author(s):  
Muhamad Fadhli Ramlee ◽  
Ahmad Fazlizan ◽  
Sohif Mat

Among renewable energy resources, wind energy is one of the best alternative for power generation. Recently, vertical axis wind turbine (VAWT) received renewed interest as small-scale wind energy converter due to its suitability for urban application, where the wind condition is known to be unsteady and turbulence. Amongst various type of VAWTs, H-type Darrieus rotor has become more popular, thanks to its simple construction features, resulting to low manufacturing and installation cost. The aim of this paper is to evaluate numerically the power performance of straight-bladed Darrieus VAWT with different turbine solidity using computational fluid dynamic (CFD) technology. A series of two-dimensional CFD simulations of a three-bladed H-type Darrieus rotor were performed with 3 different solidities, σ (0.3, 0.5 and 0.7) to evaluate their power performance. Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations were used to calculate the instantaneous moment coefficient, Cm and power coefficient, Cp over a range of tip speed ratio, λ (0.5–4.5) with a free stream velocity of 8.0 m/s. The simulation results show that high solidity turbine performed well at low values of λ while turbine with low solidity has a wider operating range of λ and performed better at λ > 3.0 due to less blade-wake interactions between upstream and downstream halves of the turbine and lower blockage effect. The findings lend substantially to our understanding of physics flow around blades and turbine in order to optimize the power performance of small scale straight-bladed Darrieus VAWT operating in unsteady and turbulence wind condition.


Author(s):  
Nicoletta Franchina ◽  
Otman Kouaissah ◽  
Giacomo Persico ◽  
Marco Savini

The paper presents the results of a computational study on the aerodynamics and the performance of a small-scale Vertical-Axis Wind Turbine (VAWT) for distributed micro-generation. The complexity of VAWT aerodynamics, which are inherently unsteady and three-dimensional, makes high-fidelity flow models extremely demanding in terms of computational cost, limiting the analysis to mainly 2D or 2.5D Computational Fluid-Dynamics (CFD) approaches. This paper discusses how a proper setting of the computational model opens the way for carrying out fully 3D unsteady CFD simulations of a VAWT. Key aspects of the flow model and of the numerical solution are discussed, in view of limiting the computational cost while maintaining the reliability of the predictions. A set of operating conditions is considered, in terms of tip-speed-ratio (TSR), covering both peak efficiency condition as well as off-design operation. The fidelity of the numerical predictions is assessed via a systematic comparison with the experimental benchmark data available for this turbine, consisting of both performance and wake measurements carried out in the large-scale wind tunnel of the Politecnico di Milano. The analysis of the flow field on the equatorial plane allows highlighting its time-dependent evolution, with the aim of identifying both the periodic flow structures and the onset of dynamic stall. The full three-dimensional character of the computations allows investigating the aerodynamics of the struts and the evolution of the trailing vorticity at the tip of the blades, eventually resulting in periodic large-scale vortices.


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