scholarly journals Canard optimization for enhancing the performance of small horizontal axis wind turbine at low wind speeds

2020 ◽  
Vol 37 ◽  
pp. 63-71
Author(s):  
Yui-Chuin Shiah ◽  
Chia Hsiang Chang ◽  
Yu-Jen Chen ◽  
Ankam Vinod Kumar Reddy
Keyword(s):  
Wind Turbine ◽  
Urban Areas ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Peak Performance ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Optimum Parameters ◽  
Low Wind Speeds

ABSTRACT Generally, the environmental wind speeds in urban areas are relatively low due to clustered buildings. At low wind speeds, an aerodynamic stall occurs near the blade roots of a horizontal axis wind turbine (HAWT), leading to decay of the power coefficient. The research targets to design canards with optimal parameters for a small-scale HAWT system operated at variable rotational speeds. The design was to enhance the performance by delaying the aerodynamic stall near blade roots of the HAWT to be operated at low wind speeds. For the optimal design of canards, flow fields of the sample blades with and without canards were both simulated and compared with the experimental data. With the verification of our simulations, Taguchi analyses were performed to seek the optimum parameters of canards. This study revealed that the peak performance of the optimized canard system operated at 540 rpm might be improved by ∼35%.

Computational Analysis of an Optimized Curved-Bladed Small-Scale Horizontal Axis Wind Turbine

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Ali M. Abdelsalam ◽  
W. A. El-Askary ◽  
M. A. Kotb ◽  
I. M. Sakr
Keyword(s):  
Wind Turbine ◽  
Flow Behavior ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Peak Performance ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Axial Thrust ◽  
Wind Speeds ◽  
Linear Profiles

Abstract This article aims to study numerically the effect of curvature of linear blade profile on the performance of small-scale horizontal axis wind turbine (SSHAWT). Rotors with two curvature types, f forward angles 5 deg, 10 deg, 15 deg, 20 deg, 30 deg, and 45 deg and backward angles −5 deg, −10 deg, and −15 deg, are investigated. Furthermore, three curvature positions of r/R = 0.8, 0.9, and 0.95 are studied. The numerical simulations are performed on rotors of radius 0.5 m at different wind speeds. The results are compared with straight rotor of linear profiles of chord and twist, which is considered as base rotor. It is found that the rotor with forward curvature of 5 deg and r/R = 0.9 has the highest power coefficient compared with the other rotors. At the peak performance, the proposed rotor reduces the axial thrust by about 12.5% compared with the base rotor. The flow behavior represented by the streamlines contours is also discussed. In such case, the separation approximately disappeared for the tip speed ratios of 5 and 6, which is responsible for the performance peak.

Basic Design and Blade Structural Analysis of a Small Horizontal-Axis Wind Turbine for Low Wind Speeds

2020 ◽  
Author(s):  
A. R. Krishnanunni ◽  
N. Datta ◽  
H. S. Chambhare ◽  
D. Swaroop
Keyword(s):  
Structural Analysis ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Weather Data ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Basic Design ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Low Wind Speeds

Abstract The basic design and blade structural analysis of a 250 W rooftop-mounted horizontal-axis wind turbine for low wind speeds is presented. A simplified non-dimensional design is first undertaken to optimize the aerodynamic performance. The non-dimensional power curve vs. the design tip speed ratio is computed with the open-source wind turbine design software QBlade. SD7062 airfoil is chosen for the blade section; and its aerodynamic efficiency is obtained for various angles of attack using XFLR5. The design process also gives the optimal chord length and pitch distribution, leading to the blade geometry. The 22-month weather data at the site has been analyzed to obtain the best-fit Weibull distribution. The blade sizing is based on the maximum power coefficient before the stall regulation happens. An attempt is made to enhance the power capture by using a concentrator, whose aerodynamic efficacy is analyzed. The blades are fabricated from Glass Fiber Reinforced Plastic, which reduces both weight and cost. The configuration for the laminate is finalized after several bending and tensile tests of five distinct GFRP samples. This is followed by the structural analysis of the blade. The root stresses and tip deflection are analyzed for extreme-wind conditions, along with the free vibration frequencies.

scholarly journals Investigation of an Innovative Rotor Modification for a Small-Scale Horizontal Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2649 ◽  
Author(s):  
Artur Bugała ◽  
Olga Roszyk
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Airflow Distribution

This paper presents the results of the computational fluid dynamics (CFD) simulation of the airflow for a 300 W horizontal axis wind turbine, using additional structural elements which modify the original shape of the rotor in the form of multi-shaped bowls which change the airflow distribution. A three-dimensional CAD model of the tested wind turbine was presented, with three variants subjected to simulation: a basic wind turbine without the element that modifies the airflow distribution, a turbine with a plano-convex bowl, and a turbine with a centrally convex bowl, with the hyperbolic disappearance of convexity as the radius of the rotor increases. The momentary value of wind speed, recorded at measuring points located in the plane of wind turbine blades, demonstrated an increase when compared to the base model by 35% for the wind turbine with the plano-convex bowl, for the wind speed of 5 m/s, and 31.3% and 49% for the higher approaching wind speed, for the plano-convex bowl and centrally convex bowl, respectively. The centrally convex bowl seems to be more appropriate for higher approaching wind speeds. An increase in wind turbine efficiency, described by the power coefficient, for solutions with aerodynamic bowls was observed.

Modeling and Performance Analysis of a Small Horizontal Axis Wind Turbine

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Osarobo Ighodaro ◽  
David Akhihiero
Keyword(s):  
Wind Turbine ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Computational Technique ◽  
Horizontal Axis Wind Turbine ◽  
Design And Optimization ◽  
Wind Speeds ◽  
Improved Design

Abstract Wind energy is increasingly becoming a major discussion amongst renewable energy sources due to its sustainability, reduced impact on the environment, and being significantly cheaper than conventional fossil fuels. Researchers have been particularly concerned with studying improved design and optimization using computational technique and experimentation. This research aims at designing blades for a small horizontal axis wind turbine for low Reynolds number using blade element momentum theory and using computational fluid dynamics (cfd) and experiment to analyze its performance. Two airfoils (SG6050 and SG6043) were selected for different regions of the blade span. Four turbulent models were used in predicting its performance. The performance was analyzed for wind speeds between 2 m/s and 7 m/s. Studies showed that the blade is capable of generating power up to 241 W with a power coefficient of 34.3% at a speed of 6 m/s. The computed power coefficient is in good agreement with experimental results of 33.7%.

scholarly journals PENGARUH KECEPATAN ANGIN DAN VARIASI JUMLAH SUDU TERHADAP UNJUK KERJA TURBIN ANGIN POROS HORIZONTAL

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Firman Aryanto ◽  
Made Mara ◽  
Made Nuarsa
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Mechanical Energy ◽  
Performance Testing ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Maximum Speed ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds

The wind turbine is a device that converts wind energy into mechanical energy and then converted into electrical energy through a generator. Horizontal axis wind turbines can increase the efficiency to get the maximum power coefficient. One was using the blade numerous. Maximum efisiensi system will increase the number of watts (power) generated so as to obtain a certain number of watts by simply using the number of windmills lessThe object of this research is the performance testing horizontal axis wind turbine with wind speed variation and variation in terms of the number of blade Efisiensi system (𝜂 )  and Tip Speed Ratio (TSR). Research conducted with the wind coming from the source to the Wind Tunnel fan to direct wind. Wind speed is used there are three variations of the 3 m/s, 3.5 m/s, and 4 m/s and varying the amount of blade that is 3, 4, 5 and 6 blade.The results showed that the best 𝜂  values obtained at a maximum wind speed of 4 m / s and the number of blade 5 with a value of 3.07% 𝜂, whereas 𝜂 smallest value obtained at wind speeds of 3 m/s and the number of blade 3 that the value of 0.05% 𝜂. For TSR maximum value at a maximum speed of 4 m/s occurred in the number of blade 5 is equal to λ = 2.11, while the lowest value at wind speeds of 3 m/s resulting in blade number 3 is equal to λ = 1.49.

scholarly journals Design and Fabrication of Multi-Rotor Horizontal Axis Wind Turbine

2019 ◽  
Vol 8 (6) ◽  
pp. 3500-3504 ◽  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Poor Performance ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Start Up ◽  
Overall Performance ◽  
Low Wind Speeds ◽  
The Cost

Wind is an endless resource which is abundantly found in nature. Harnessing wind energy for producing electricity is one of the ways for buildings for a sustainable future. Small-scale wind turbines could be a reliable energy source for usage in homes and in autonomous applications in locations that are far away from the grid power. Small wind turbines operating at low wind speeds regularly face the problem of poor performance due to small rotor size. To increase the power production additional wind turbines are installed. This increases the overall cost of the project. To reduce the cost and to improve the efficiency, multiple rotors are connected through a single shaft to the fixed single generator. The Implementation of this design permits start up at lower wind speeds, increasing the start-up torque and thus improving the overall performance of the turbine. This paper elaborates the design and fabrication of such a wind turbine. [1] [2] [3]

scholarly journals Effect of Wind Tunnel Blockage on the Performance of a Horizontal Axis Wind Turbine with Different Blade Number

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1988 ◽  
Author(s):  
Abdelgalil Eltayesh ◽  
Magdy Bassily Hanna ◽  
Francesco Castellani ◽  
A.S. Huzayyin ◽  
Hesham M. El-Batsh ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Computational Effort ◽  
Horizontal Axis ◽  
Experimental Results ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Cross Section Area

Blockage corrections for the experimental results obtained for a small-scale wind turbine in a wind tunnel are required in order to estimate how the same turbine would perform in real conditions. The tunnel blockage is defined as the ratio of the wind turbine swept area to the wind tunnel cross-section area. Experimental measurements of the power coefficient were performed on a horizontal-axis wind turbine with two rotors of diameter equal to 2 m and different numbers of blades, namely three and five. Measurements were carried out for different tip speed ratios in the closed circuit open test section wind tunnel of the University of Perugia (Italy). The obtained experimental results were compared with the numerical ones carried out in free conditions by using a CFD approach based on the steady-RANS method with the SST k-ω turbulence model, adopting the multiple reference frame (MRF) strategy to reduce the computational effort. The comparison showed that the maximum value of blockage, which is reached in the asymptotic limit at very large tip speed ratio (TSR) values, does not depend appreciably on the number of blades. A higher number of blades, however, makes the occurrence of the maximum blockage come earlier at lower TSRs.

Investigation of multi rotor small horizontal axis wind turbine at low wind speeds

2020 ◽  
Author(s):  
Manoj Kumar Chaudhary ◽  
S. Prakash ◽  
Tejas Hulawale ◽  
Aditya Shekhar ◽  
Prabhakar Gavade ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Low Wind Speeds

Small Horizontal Axis Wind Turbine: Analytical Blade Design and Comparison With RANS-Prediction and First Experimental Data

2013 ◽  
Author(s):  
Tom Gerhard ◽  
Michael Sturm ◽  
Thomas H. Carolus
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Analytical Models ◽  
Power Coefficient ◽  
Analysis Tool ◽  
Computational Domain ◽  
Horizontal Axis Wind Turbine ◽  
Data Set

State-of-the-art wind turbine performance prediction is mainly based on semi-analytical models, incorporating blade element momentum (BEM) analysis and empirical models. Full numerical simulation methods can yield the performance of a wind turbine without empirical assumptions. Inherent difficulties are the large computational domain required to capture all effects of the unbounded ambient flow field and the fact that the boundary layer on the blade may be transitional. A modified turbine design method in terms of the velocity triangles, Euler’s turbine equation and BEM is developed. Lift and drag coefficients are obtained from XFOIL, an open source 2D design and analysis tool for subcritical airfoils. A 3 m diameter horizontal axis wind turbine rotor was designed and manufactured. The flow field is predicted by means of a Reynolds-averaged Navier-Stokes simulation. Two turbulence models were utilized: (i) a standard k-ω-SST model, (ii) a laminar/turbulent transition model. The manufactured turbine is placed on the rooftop of the University of Siegen. Three wind anemometers and wind direction sensors are arranged around the turbine. The torque is derived from electric power and the rotational speed via a calibrated grid-connected generator. The agreement between the analytically and CFD-predicted kinematic quantities up- and downstream of the rotor disc is quite satisfactory. However, the blade section drag to lift ratio and hence the power coefficient vary with the turbulence model chosen. Moreover, the experimentally determined power coefficient is considerably lower as predicted by all methods. However, this conclusion is somewhat preliminary since the existing experimental data set needs to be extended.

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°.

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