scholarly journals Numerical investigation of stall characteristics for winglet blade of a horizontal axis wind turbine

2021 ◽  
Vol 321 ◽  
pp. 03004
Author(s):  
Shalini Verma ◽  
Akshoy Ranjan Paul ◽  
Anuj Jain ◽  
Firoz Alam

Wind energy is one of the renewable energy resources which is clean and sustainable energy and the wind turbine is used for harnessing energy from the wind. The blades are the key components of a wind turbine to convert wind energy into rotational energy. Recently, wingtip devices are used in the blades of horizontal axis wind turbine (HAWT), which decreases the vortex and drag, while increases the lift and thereby improve the performance of the turbine. In the present study, a winglet is used at the tip of an NREL phase VI wind turbine blade. Solidworks, Pointwise, and Ansys-Fluent are used for geometric modeling, computational grid generation, and CFD simulation, respectively. The computational result obtained using SST k-ω turbulence modeling is well validated with the experimental data of NREL at 5 and 7 m/s of wind speeds. Numerical investigation of stall characteristics is carried out for wingleted blade at higher turbulence intensity (21% and 25%) and angle of attack (00 to 300 at 50 intervals) at 7 m/s wind speed. The result found that wingletd blade delay stall to 150 for both the cases of turbulence intensity. Increasing the turbulence intensity increases the lift coefficient at stall angle but drag coefficient also increases and thus a lower aerodynamic performance (CL/CD ratio = 13) is obtained. Wingleted blade improves the performance as the intensity of vortices is smaller compared to baseline blade

Author(s):  
Hagninou E. V. Donnou ◽  
Drissa Boro ◽  
Jean Noé Fabiyi ◽  
Marius Tovoeho ◽  
Aristide B. Akpo

In the present work, the study and design of a horizontal axis wind turbine suitable for the Cotonou site were investigated on the coast of Benin. A statistical study using the Weibull distribution was carried out on the hourly wind data measured at 10 m from the ground by the Agency for Air Navigation Safety in Africa and Madagascar (ASECNA) over the period from January 1981 to December 2014. Then, the models, techniques, tools and approaches used to design horizontal axis wind turbines were presented and the wind turbine components characteristics were determined. The numerical design and assembly of these components were carried out using SolidWorks software. The results revealed that the designed wind turbine has a power of 571W. It is equipped with a permanent magnet synchronous generator and has three aluminum blades with NACA 4412 biconvex asymmetrical profile. The values obtained for the optimum coefficient of lift and drag are estimated at 1.196 and 0.0189 respectively. The blades are characterised by an attack optimum angle estimated at 6° and the wedge angle at 5°. Their length is 2.50 m and the maximum thickness is estimated at 0.032 m for a rope length of 0.27 m. The wind turbine efficiency is 44%. The computer program designed on SolidWorks gives three-dimensional views of the geometrical shape of the wind turbine components and their assembly has allowed to visualize the compact shape of the wind turbine after export via its graphical interface. The energy quantity that can be obtained from the wind turbine was estimated at 2712,718 kWh/year. This wind turbine design study is the first of its kind for the study area. In order to reduce the technological dependence and the import of wind energy systems, the results of this study could be used to produce lower cost wind energy available on our study site.


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):  
Manoj Kumar Chaudhary ◽  
◽  
S. Prakash ◽  

In this research work, the investigation and optimization of small horizontal axis wind turbine blade at low wind speed is pursued. The experimental blades were developed using the 3D printing additive manufacturing technique. The airfoils E210, NACA2412, S1223, SG6043, E216, NACA4415, SD7080, SD7033, S1210 and MAF were tested at the wind speed of 2-6 m/s. The airfoils and optimum blade geometry were investigated with the aid of the Xfoil software at Reynolds number of 100,000. The initial investigation range included tip speed ratios from 3 to 10, solidity from 0.0431 – 0.1181 and angle of attacks from 2o to 20o. Later on these parameters were varied in MATLAB and Xfoil software for optimization and investigation of the power coefficient, lift coefficient, drag coefficient and lift to drag ratio. The cut-in wind speed of the rotors was 2 and 2.5 m/s with the winglet-equipped blades and without winglets. It was found that the E210, SG6043, E216 NACA4415 and MAF airfoil displayed better performance than the NACA 2412, S1223, SD7080, S1210 & SD7003 for the geometry optimized for the operating conditions and manufacturing method described.


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