Modeling and Performance Analysis of a Small Horizontal Axis Wind Turbine

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Osarobo Ighodaro ◽  
David Akhihiero

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%.

2020 ◽  
Vol 37 ◽  
pp. 63-71
Author(s):  
Yui-Chuin Shiah ◽  
Chia Hsiang Chang ◽  
Yu-Jen Chen ◽  
Ankam Vinod Kumar Reddy

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%.


2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Ali M. Abdelsalam ◽  
W. A. El-Askary ◽  
M. A. Kotb ◽  
I. M. Sakr

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.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4983 ◽  
Author(s):  
Miguel Sumait Sy ◽  
Binoe Eugenio Abuan ◽  
Louis Angelo Macapili Danao

Wind energy is one of the fastest growing renewable energy sources, and the most developed energy extraction device that harnesses this energy is the Horizontal Axis Wind Turbine (HAWT). Increasing the efficiency of HAWTs is one important topic in current research with multiple aspects to look at such as blade design and rotor array optimization. This study looked at the effect of wingtip devices, a split winglet, in particular, to reduce the drag induced by the wind vortices at the blade tip, hence increasing performance. Split winglet implementation was done using computational fluid dynamics (CFD) on the National Renewable Energy Lab (NREL) Phase VI sequence H. In total, there are four (4) blade configurations that are simulated, the base NREL Phase VI sequence H blade, an extended version of the previous blade to equalize length of the blades, the base blade with a winglet and the base blade with split winglet. Results at wind speeds of 7 m/s to 15 m/s show that adding a winglet increased the power generation, on an average, by 1.23%, whereas adding a split winglet increased it by 2.53% in comparison to the extended blade. The study also shows that the increase is achieved by reducing the drag at the blade tip and because of the fact that the winglet and split winglet generating lift themselves. This, however, comes at a cost, i.e., an increase in thrust of 0.83% and 2.05% for the blades with winglet and split winglet, respectively, in comparison to the extended blade.


2014 ◽  
Vol 1079-1080 ◽  
pp. 543-546 ◽  
Author(s):  
Zhi Kui Wang ◽  
Yi Bao Chen ◽  
Gwo Chung Tsai

The wind turbines have gained a wide range of applications in Renewable Energy Sources (RES) by virtue of its dominant advantages, and it has achieved almost the state-of-the-art from the engineering point of view. Nevertheless, the starting behavior which plays a prominent role in wind power generation has achieved few studies up to this moment. We conducted this analysis of a micro horizontal axis wind turbine (MHAWT) on its starting behavior to give insight into its start-up torque as well as its start-up speed on an assumption that it is rigid body, and some relative simplification on its structure are adopted meanwhile. The wind turbine's power coefficient CP, tip-speed-ratio l along with torque coefficient CT were taken into consideration and discussed to a large extent in order to having a relative clear cognition of its operational characteristics.


2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Firman Aryanto ◽  
Made Mara ◽  
Made Nuarsa

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.


Author(s):  
A. R. Krishnanunni ◽  
N. Datta ◽  
H. S. Chambhare ◽  
D. Swaroop

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.


Author(s):  
Tom Gerhard ◽  
Michael Sturm ◽  
Thomas H. Carolus

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.


Author(s):  
P. Venkaiah ◽  
B. K. Sarkar

Abstract The advantages of renewable energy sources are available freely in nature, inexhaustible, produce either no or little pollution and low gestation period. Among all renewable energy sources, wind energy has become one of the leading resources for power production in the world as well as in the India. According to WWEA, the wind turbine installation capacity in the world has been reached over 539.291GW by the end of 2017. The entire wind power installed capacity by the end of 2017 covers more than 5% of global demand of electricity. In India, the present wind power installation capacity on October, 2017 was over 32.7GW and wind energy contribution is 55% of the total renewable energy capacity in the country. Inspite of having sharp growth rate in wind in India, only a fraction of wind energy has been tapped until now out of 302 GW wind potential which is available above 100 m height on shore. Practical horizontal axis wind turbine converts kinetic energy in the wind into useful energy by using airfoil blades. Blade element momentum (BEM) theory becomes very popular due to its simplicity in mathematical calculation as well as accuracy. Hydraulic pitch actuation system has certain advantages due to its versatility, ability to produce constant force and torque irrespective of the disturbances outside of the system, ease and accuracy of control, simplicity, safety and economy. In the present study a semi rotary actuator has been utilized for turbine pitch actuation. In order to extract maximum power from available wind, fractional order PID controller (FOPID) has been developed for pitch control of wind turbine rotor blade. The performances of PID as well as FOPID controller have been compared with available wind data. The performance of FOPID controller was satisfactory compare to PID controller.


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2649 ◽  
Author(s):  
Artur Bugała ◽  
Olga Roszyk

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.


Author(s):  
Ohad Gur ◽  
Aviv Rosen

The optimal aerodynamic design of Horizontal Axis Wind Turbine (HAWT) is investigated. The Blade-element/Momentum model is used for the aerodynamic analysis. In the first part of the paper a simple design method is derived, where the turbine blade is optimized for operation at a specific wind speed. Results of this simple optimization are presented and discussed. Besides being optimized for operation at a specific wind speed, without considering operation at other wind speeds, the simple model is also limited in the choice of design goals (cost functions), design variables and constraints. In the second part of the paper a comprehensive design method that is based on a mixed numerical optimization strategy, is presented. This method can handle almost any combination of: design goal, design variables, and constraints. Results of this method are presented, compared with the results of the simple optimization, and discussed.


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