Experimental Study of a Straight-Bladed Vertical Axis Wind Turbine With a Directed Guide Vane Row

2009 ◽  
Author(s):  
Manabu Takao ◽  
Hiroyuki Takita ◽  
Yohei Saito ◽  
Takao Maeda ◽  
Yasunari Kamada ◽  
...  
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Velocity ◽  
Guide Vane ◽  
Vertical Axis ◽  
Chord Length ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes ◽  
Blade Height

The objective of this study is to show the effect of guide vane geometry on the performance of wind turbine. In order to overcome the disadvantages of vertical axis wind turbine, a straight-bladed vertical axis wind turbine (S-VAWT) with a directed guide vane row has been proposed and tested by the authors. According to previous studies, it was clarified that the performance of the turbine can be improved by means of the directed guide vane row. However, the guide vane geometry of S-VAWT has not been optimized so far. In order to clarify the effect of guide vane geometry, the effects of distance between the guide vanes and the number of guide vanes on power and torque coefficients were investigated in the experiments. The experimental study was carried out by a wind tunnel. The wind tunnel with a diameter of 1.8m is open jet type. The wind velocity is from 5 to 9 m/s in the experiments. The rotor has three straight blades with a profile of NACA4518 and a chord length of 100 mm, a diameter of 0.6 m and a blade height of 0.7 m. The guide vane row consists of some arc plates.

scholarly journals Performance Analysis of Highway Wind Turbine Enhanced with Wind Guide Vanes Using the Taguchi Method

CFD letters ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 25-42
Author(s):  
Mohamad Zahid Mazlan ◽  
Fazila Mohd Zawawi ◽  
Teeab Tahzib ◽  
Kamarulafizam Ismail ◽  
Syahrullail Samion
Keyword(s):  
Taguchi Method ◽  
Wind Turbine ◽  
Wind Velocity ◽  
Guide Vane ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes ◽  
Moving Vehicle ◽  
Low Wind Speed

Considerable efforts have been made by researchers to study the interaction between moving vehicles and wind turbines. The Savonius vertical-axis wind turbine was chosen due to its effectiveness in low-wind speed conditions. Speeding vehicles produce a scattered and non-uniform wind flow with disturbances. Hence, to prevent a negative torque, a row of wind guide vane panels was arranged in front of the blades of a wind turbine. The wind guide vane had the shape of an NACA4412 aerofoil to reduce the loss of wind energy, and to further increase wind velocity. A number of CFD simulations were designed using the Taguchi method to determine the optimum conditions for the power coefficient of the wind turbine in terms of the effects of three factors, namely, the distance between the guide vanes (d), the angle of the guide vanes (?), and the speed of the moving car (VC). An orthogonal array of L9(33) was designed. In addition, to observe the effects of the wind velocity induced by the moving vehicle, the wind turbine was incorporated with one degree of freedom (1DOF). The results showed that the speed of the moving car played a major role in determining the power coefficient. The order of influence of each factor was ranked as VC > ? > d. The performance of the wind turbine was sensitive to the speed of the car and the angle of the guide vanes, whereas it was insensitive to the distance between the guide vanes. Furthermore, the analysis of the signal-to-noise (S/N) ratio suggested that the optimal combination of factors for a maximum power coefficient were d = 0.4m, ? = 30°, and VC =30m/s. The optimum setting increased the Cp to 26% compared to the Cp that was produced without the installation of the guide vanes.

A Straight-Bladed Vertical Axis Wind Turbine With a Directed Guide Vane Row

2007 ◽  
Author(s):  
Manabu Takao ◽  
Takao Maeda ◽  
Yasunari Kamada ◽  
Michiaki Oki ◽  
Hideki Kuma
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Aerodynamic Force ◽  
Guide Vane ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Turbine

A straight-bladed vertical axis wind turbine with a directed guide vane row has been proposed in order to enhance its torque. The experimental study of the proposed wind turbine was carried out by a wind tunnel with an outlet diameter of 1.8m. The tested rotor has some straight rotor blades with a profile of NACA0015, a radius diameter of 0.3 m and a height of 0.7 m. The guide vane row having 3 arc plates rotates around the rotor and is directed to the wind by aerodynamic force generated by tail vanes, so as to put the guide vane row in upstream of the rotor. As a result, the performance of the straight-bladed vertical axis turbine was improved by means of the directed guide vane row. Further, by the use of the guide vane row adopted in the study, the power coefficient of the proposed wind turbine was approximately 1.5 times higher than that of the original wind turbine which has no guide vane.

Computational fluid dynamic analysis of roof-mounted vertical-axis wind turbine with diffuser shroud, flange, and vanes

2018 ◽  
Vol 42 (4) ◽  
pp. 404-415
Author(s):  
H. Abu-Thuraia ◽  
C. Aygun ◽  
M. Paraschivoiu ◽  
M.A. Allard
Keyword(s):  
Wind Turbine ◽  
Urban Areas ◽  
Guide Vane ◽  
Fluid Dynamic ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes ◽  
Turbine Design

Advances in wind power and tidal power have matured considerably to offer clean and sustainable energy alternatives. Nevertheless, distributed small-scale energy production from wind in urban areas has been disappointing because of very low efficiencies of the turbines. A novel wind turbine design — a seven-bladed Savonius vertical-axis wind turbine (VAWT) that is horizontally oriented inside a diffuser shroud and mounted on top of a building — has been shown to overcome the drawback of low efficiency. The objective this study was to analyze the performance of this novel wind turbine design for different wind directions and for different guide vanes placed at the entrance of the diffuser shroud. The flow field over the turbine and guide vanes was analyzed using computational fluid dynamics (CFD) on a 3D grid for multiple tip-speed ratios (TSRs). Four wind directions and three guide-vane angles were analyzed. The wind-direction analysis indicates that the power coefficient decreases to about half when the wind is oriented at 45° to the main axis of the turbine. The analysis of the guide vanes indicates a maximum power coefficient of 0.33 at a vane angle of 55°.

An Experimental Study of the Aerodynamics and Performance of a Vertical Axis Wind Turbine in a Confined and Unconfined Environment

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Vincenzo Dossena ◽  
Giacomo Persico ◽  
Berardo Paradiso ◽  
Lorenzo Battisti ◽  
Sergio Dell'Anna ◽  
...  
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Tip Vortex ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Tip Speed Ratio ◽  
And Performance ◽  
Power Curves

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.

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.

Simulation and Test for Two Airfoils with Wind Guide Vane of VAWT

2010 ◽  
Vol 148-149 ◽  
pp. 1199-1203
Author(s):  
Guo Qing Wu ◽  
Xinghua Chen ◽  
Yang Cao ◽  
Jing Ling Zhou
Keyword(s):  
Wind Tunnel ◽  
Wind Energy ◽  
Wind Turbine ◽  
Guide Vane ◽  
Vertical Axis ◽  
Performance Data ◽  
Vertical Axis Wind Turbine ◽  
Different Types

Two airfoils of vertical axis wind turbine (VAWT) were designed, and the wind guide vane was added for VAWT. By using Fluent and the environment wind tunnel, some results were simulated and tested for two different types of airfoils and its wind guide vane. The performance data on certain condition was obtained. Research showed that utilization of wind energy with guide vane wind turbine was higher than those without guide vane structure. The performance of airfoil was more excellent than airfoil . Wind guide vane structure is a new structure for wind turbine which will have a wide prospect.

scholarly journals Investigations of a vertical axis wind turbine with frontal cylindrical guide vane unit

2021 ◽  
Vol 327 ◽  
pp. 04005
Author(s):  
Valentin Obretenov ◽  
Rossen Iliev
Keyword(s):  
Wind Turbine ◽  
Numerical Study ◽  
Guide Vane ◽  
Vertical Axis ◽  
Vertical Wind ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes ◽  
Flow Through ◽  
Guide Device ◽  
Positive Effect

The paper presents the results of an experimental study of a vertical wind turbine type Darrieus with frontal cylindrical guide vane unit. The main goal of the research is to analyze the influence of the geometry of a classical cylindrical guide vane unit on the active and passive zone of the wind turbine. The aerodynamic scheme is synthesized by a classic runner and frontal cylindrical guide vanes. Three different guiding devices of a model vertical wind turbine with frontally located guide vanes have been studied. Their influence on the characteristics of the turbine has been examined. The reasons of the differences in the characteristics of the three studied variants of the guiding devices are clarified by numerical study of the flow through the blade cascades of the guide vanes and the runner. The results of the study shows what is the reason for the positive effect of the cylindrical vane guide device on the wind turbine’s runner.

An Experimental Study of the Aerodynamics and Performance of a Vertical Axis Wind Turbine in Confined and Non-Confined Environment

2015 ◽  
Author(s):  
Vincenzo Dossena ◽  
Giacomo Persico ◽  
Berardo Paradiso ◽  
Lorenzo Battisti ◽  
Sergio Dell’Anna ◽  
...  
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Tip Vortex ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
And Performance ◽  
Confined Environment ◽  
Power Curves

This paper presents the results of a wide experimental study on an H-type Vertical Axis Wind Turbine (VAWT) carried out at Politecnico di Milano in the frame of the national founded project PRIN 2009. The experiments were carried out in the large-scale wind tunnel of the Politecnico di Milano, where real-scale wind turbines for micro generation can be tested in full similarity 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 confined and non-confined 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 λ = 2.5. Detailed flow measurements, performed in three conditions for λ 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 non-symmetrical wake and tip vortex are found. The unsteady evolution of the velocity and turbulence fields further highlight the effect of aerodynamic loading on the wake unsteadiness, showing the time-dependent nature of the tip vortex and the onset of a non-symmetric dynamic stall for λ lower than 2.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

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