Analysis of Senegal Type Vertical Axis Wind Turbines Arrangement in Wind Farm

2019 ◽  
Vol 13 ◽  
Author(s):  
Li Zheng ◽  
Zhang Wenda ◽  
Han Ruihua ◽  
Qi Weiqiang

Background: In a wind farm, the wind speed of the downstream wind turbine will be lower than the wind speed of the upstream wind turbine due to the influence of the wake. Therefore, the wake of wind turbines is one of the uncertain factors predicting the annual power generation of wind farms. The study of the wake can effectively improve the efficiency of power generation. The arrangement of vertical axis wind turbines in wind farms is rarely studied. Therefore, it is important to study the vertical layout of wind turbines under the influence of wakes to obtain the best layout and unit spacing. Objective: To obtain the optimal layout and unit distance of wind turbines in Senegal wind turbines by studying the arrangement of Senegal vertical axis wind turbines in wind farms. Method: Based on the ANSYS CFX flow field calculation module, the fluid dynamics model of the Senegal fan was established and the flow field simulation analysis was carried out. Based on the Jensen wake model and its improved model, three layout methods for wind farm wind turbines are proposed: two units are arranged in series, two units are arranged in parallel, and three units are staggered. Through the simulation model, the wind energy utilization coefficient and wind speed of the wind turbine in the wind farm are obtained. Results: The optimal separation distance between the units was analyzed from four different angles: wind energy utilization coefficient, torque analysis, downstream tail flow and wind speed cloud contour. Finally, based on the optimal arrangement and unit distance, a triangular staggered wind farm composed of 10 units is established, and the integrated flow field characteristics of the whole wind farm are simulated and analyzed. The integrated flow field wake characteristics of the wind farm are obtained. Conclusion: In all three arrangements, the optimum distance between the units should be three times the diameter of the wind turbine. This arrangement ensures that most of the units are unaffected by the wake, the area affected by the low velocity wake of the wind farm is small, and the area affected by the high speed wake is large.

2020 ◽  
Vol 12 (18) ◽  
pp. 7818
Author(s):  
Jose Alberto Moleón Baca ◽  
Antonio Jesús Expósito González ◽  
Candido Gutiérrez Montes

This paper presents a numerical and experimental analysis of the patent of a device to be used in vertical-axis wind turbines (VAWTs) under extreme wind conditions. The device consists of two hemispheres interconnected by a set of conveniently implemented variable section ducts through which the wind circulates to the blades. Furthermore, the design of the cross-section of the ducts allows the control of the wind speed inside the device. These ducts are intended to work as diffusers or nozzles, depending on the needs of the installation site. Simulations were performed for the case of high-speed external wind, for which the ducts act as diffusers to reduce wind speed and maintain a well-functioning internal turbine. Four different patent designs were analyzed, focusing on turbine performance and generated power. The results indicate that the patent allows the generation of electric power for a greater range of wind speeds than with a normal wind turbine. The results support that this patent may be a good alternative for wind power generation in geographic areas with extreme weather conditions or with maintained or strong gusty wind. Experimental tests were carried out on the movement of the blades using the available model. Finally, the power curve of the model of this wind turbine was obtained.


2021 ◽  
Vol 12 (1) ◽  
pp. 6
Author(s):  
Tahir Abbas Jauhar ◽  
Sajjad Miran ◽  
Waseem Arif ◽  
Asad Muneer ◽  
Zara Mukaddas

Technological advancements have improved energy efficiency and increased energy requirements requiring improved energy density solutions to optimally utilize the existing landscape. The renewable energy density of urban rooftops can be increased by introducing micro wind farms consisting of vertical axis wind turbines (VAWT). VAWTs do not require directed flow thus a feasible choice. In this paper, the preliminary study for parametric design of horizontal distance between two identical Savonius wind turbines is presented. Three different simulations were performed to reveal important insights about this problem with an inlet velocity of 2 m/s. The results suggest 3D analysis for accurate insights.


Author(s):  
L. Battisti ◽  
L. Zanne ◽  
S. Dell’Anna ◽  
V. Dossena ◽  
B. Paradiso ◽  
...  

This paper presents the first results of a wide experimental investigation on the aerodynamics of a vertical axis wind turbine. Vertical axis wind turbines have recently received particular attention, as interesting alternative for small and micro generation applications. However, the complex fluid dynamic mechanisms occurring in these machines make the aerodynamic optimization of the rotors still an open issue and detailed experimental analyses are now highly recommended to convert improved flow field comprehensions into novel design techniques. The experiments were performed in the large-scale wind tunnel of the Politecnico di Milano (Italy), where real-scale wind turbines for micro generation can be tested in full similarity conditions. Open and closed wind tunnel configurations are considered in such a way to quantify the influence of model blockage for several operational conditions. Integral torque and thrust measurements, as well as detailed aerodynamic measurements were applied to characterize the 3D flow field downstream of the turbine. The local unsteady flow field and the streamwise turbulent component, both resolved in phase with the rotor position, were derived by hot wire measurements. The paper critically analyses the models and the correlations usually applied to correct the wind tunnel blockage effects. Results evidence that the presently available theoretical correction models does not provide accurate estimates of the blockage effect in the case of vertical axis wind turbines. The tip aerodynamic phenomena, in particular, seem to play a key role for the prediction of the turbine performance; large-scale unsteadiness is observed in that region and a simple flow model is used to explain the different flow features with respect to horizontal axis wind turbines.


2018 ◽  
Vol 43 (2) ◽  
pp. 201-209
Author(s):  
Gino Iannace ◽  
Amelia Trematerra ◽  
Umberto Berardi

In Italy, wind turbines with a nominal power below 1 MW can be installed following simplified authorization procedures and are therefore becoming the preferred choice for promoters. The assessment of the noise of wind farms is not easy, due to economic reasons, with it being difficult to stop and assess the relative contribution of each wind turbine. Several acoustic measurements were taken inside homes located near a wind farm consisting of three wind turbines, each with a nominal power of 1 MW. The acoustic measurements were taken by placing sound level meters inside the houses at different wind speed values and wind directions. The acoustic measurements were taken using the acoustically analogous place technique. For economic reasons, the plant cannot be switched off. In this case, the sound field generated by the operation of the wind turbines was measured by placing two sound level meters in a house.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wang Wenxin ◽  
Chen Kexin ◽  
Bai Yang ◽  
Xu Yun ◽  
Wang Jianwen

AbstractGiven the increasing trend of using wind energy in cities, the utilization of distributed wind energy in cities has been widely concerned by researchers. The related research on the micro-site selection of wind turbines, a sub-project of the Task27 project of the International energy agency, was continued in this paper. The wind speed data of an observation station near Hohhot, Inner Mongolia, with a range of 10–19 m were collected. The evaluation included wind direction, Weibull parameter characteristics, and turbulence intensity. The potential energy output in 10 different heights was estimated using commercial horizontal and vertical axis wind turbines of the same power. Results showed that the following: the three-parameter Weibull distribution model can well describe the statistical properties of the wind speed in this site. The wind speed distribution model constructed from extrapolation parameters reflects the wind speed statistical properties out of detection positions to a certain extent. The wind energy density of the vertical axis wind turbine is slightly lower than that of the horizontal axis wind turbine. Furthermore, more power can be generated from March to May.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8000
Author(s):  
Abel Arredondo-Galeana ◽  
Feargal Brennan

The offshore wind sector is expanding to deep water locations through floating platforms. This poses challenges to horizontal axis wind turbines (HAWTs) due to the ever growing size of blades and floating support structures. As such, maintaining the structural integrity and reducing the levelised cost of energy (LCoE) of floating HAWTs seems increasingly difficult. An alternative to these challenges could be found in floating offshore vertical axis wind turbines (VAWTs). It is known that VAWTs have certain advantages over HAWTs, and in fact, some small-scale developers have successfully commercialised their onshore prototypes. In contrast, it remains unknown whether VAWTs can offer an advantage for deep water floating offshore wind farms. Therefore, here we present a multi-criteria review of different aspects of VAWTs to address this question. It is found that wind farm power density and reliability could be decisive factors to make VAWTs a feasible alternative for deep water floating arrays. Finally, we propose a way forward based on the findings of this review.


2014 ◽  
Vol 953-954 ◽  
pp. 395-399 ◽  
Author(s):  
Lih Shyng Shyu

The purpose of this study is to investigate the parameters that affect the cost-effectiveness of wind farm land use and wind energy harvesting efficiency. The research team applies two reverse rotating vertical-axis wind turbines (VAWTs) to explore how wind speed and various distances of wind turbines affect the operation efficiency of a prospective wind farm. A data acquisition system has been constructed to record the wind speed along with a variety of wind turbine output data in a wind tunnel test in order to identify the layout that help to achieve the best wind harvesting efficiency. The layout is then applied in the field test for further observation and data collection. The experiment results show 1) when two VAWTs are moved toward each other (from 300 cm to 180 cm), both turbines observe performance gain, and 2) when two VAWTs are set at a distance of 1.5 to 2.0 times the turbine diameter, the performance of both units increases by about 11% over the efficiency obtainable by their stand-alone counterpart.


2015 ◽  
Vol 793 ◽  
pp. 388-392
Author(s):  
Farhan Ahmed Khammas ◽  
Kadhim Hussein Suffer ◽  
Ryspek Usubamatov ◽  
Mohmmad Taufiq Mustaffa

This paper reviews the available types of wind turbine which is one of the wind energy applications. The authors intend to give investors a better idea of which turbine is suitable for a particular setting and to provide a new outlook on vertical axis wind turbines. Wind technology has grown substantially since its original use as a method to grind grains and will only continue to grow. Vertical-axis wind turbines are more compact and suitable for residential and commercial areas while horizontal-axis wind turbines are more suitable for wind farms in rural areas or offshore. However, technological advances in vertical axis wind turbines that are able to generate more energy with a smaller footprint are now challenging the traditional use of horizontal wind turbines in wind farms. Vertical axis wind turbines do not need to be oriented to the wind direction and offer direct rotary output to a ground-level load, making them particularly suitable for water pumping, heating, purification and aeration, as well as stand-alone electricity generation. The use of high efficiency Darrieus turbines for such applications is virtually prohibited by their inherent inability to self-start.


2020 ◽  
Author(s):  
wang Wenxin ◽  
Bai Yang ◽  
Chen Kexin ◽  
Wang Jianwen ◽  
Qin Chaofan

Abstract Background:Given the increasing trend of using wind energy in cities, the utilization of distributed wind energy in cities has been widely concerned by researchers. The related research on the micro-site selection of wind turbines, a sub-project of the Task27 project of the International energy agency, was continued in this paper.Methods:The wind speed data of an observation station near Hohhot, Inner Mongolia, with a range of 10-19 m were collected. The evaluation included wind direction, Weibull parameter characteristics, and turbulence intensity. The potential energy output in 10 different heights was estimated using commercial horizontal and vertical axis wind turbines of the same power.Results:The three-parameter Weibull distribution model can well describe the statistical properties of the wind speed in this site. The wind speed distribution model constructed from extrapolation parameters reflects the wind speed statistical properties out of detection positions to a certain extent.Conclusions:The wind energy density of the vertical axis wind turbine is slightly lower than that of the horizontal axis wind turbine. Furthermore, more power can be generated from March to May.


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.


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