scholarly journals CFD Comparative Study on Bended and 2D Airfoils on HAWT Performance

2021 ◽  
Vol 2128 (1) ◽  
pp. 012031
Author(s):  
Ahmed H S Yassin ◽  
Sameh M Shabaan ◽  
Amany Khaled
Keyword(s):  
Aerodynamic Characteristics ◽  
Power Coefficient ◽  
Horizontal Axis Wind Turbine ◽  
Circular Section ◽  
Design Point ◽  
Wind Speeds ◽  
Turbine Efficiency ◽  
Rotating Blade ◽  
Low Wind Speeds ◽  
2D Airfoil

Abstract The design of a conventional horizontal axis wind turbine (HAWT) is based on the aerodynamic characteristics of a two-dimensional (2D) airfoil. The rotational motion and the consequent aerodynamic effects, of HAWT’s rotor, do not guarantee an optimal design point that matches the 2D airfoil characteristics. The present work studies the diversion of the flow due to the spanwise velocity component in a rotating reference frame. It suggests that a slight deviation in the flow away from the chordwise direction could alternate the characteristics of the airfoil profile. A bended profile with a circular arc was extracted from a baseline rotating blade, flattened, and modelled against the 2D S826 airfoil. The results show a substantial discrepancy in the airfoil characteristics which could influence the turbine efficiency. Therefore, it suggests using a pre-bended airfoil (3D) while modeling the blade, so the circular section will match the correct airfoil coordinates. The proposed bended-profile version was modeled against the baseline blade. This novel blade shows an augmentation in the power coefficient up to 5.4% starting from the design point to high tip speed ratios (TSR) and low wind speeds.

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%.

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 Dependence of Power Characteristics on Savonius Rotor Segmentation

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2912
Author(s):  
Krzysztof Doerffer ◽  
Janusz Telega ◽  
Piotr Doerffer ◽  
Paulina Hercel ◽  
Andrzej Tomporowski
Keyword(s):  
High Wind ◽  
Horizontal Axis Wind Turbine ◽  
Savonius Rotor ◽  
Power Characteristics ◽  
Wind Speeds ◽  
Single Segment ◽  
High Elongation ◽  
Low Wind Speeds ◽  
Number Of Segments ◽  
Rotor Type

Savonius rotors are large and heavy because they use drag force for propulsion. This leads to a larger investment in comparison to horizontal axis wind turbine (HAWT) rotors using lift forces. A simple construction of the Savonius rotor is preferred to reduce the production effort. Therefore, it is proposed here to use single-segment rotors of high elongation. Nevertheless, this rotor type must be compared with a multi-segment rotor to prove that the simplification does not deteriorate the effectiveness. The number of segments affects the aerodynamic performance of the rotor, however, the results shown in the literature are inconsistent. The paper presents a new observation that the relation between the effectiveness of single- and multi-segment rotors depends on the wind velocity. A single-segment rotor becomes significantly more effective than a four-segment rotor at low wind speeds. At high wind speeds, the effectiveness of both rotors becomes similar.

scholarly journals Pengaruh diameter dan jumlah sudu turbin angin savonius tipe L terhadap unjuk kerja yang dihasilkan

2020 ◽  
Vol 1 (2) ◽  
pp. 61-67
Author(s):  
Mohammad Rizqi Saputra ◽  
Nur Kholis ◽  
Mohammad Munib Rosadi
Keyword(s):  
Energy Source ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Mechanical Energy ◽  
Simulation Method ◽  
Wind Speeds ◽  
Turbine Efficiency ◽  
Analysis Technique ◽  
Low Wind Speeds ◽  
Wind Source

Abstract Wind is a renewable mechanical energy source that can be used as an energy source because the energy from the wind can be used to drive wind turbines. Savonius wind turbine type L is a tool to convert wind energy into electricity with a simple construction and can work with low wind speeds. The purpose of this study was to determine the effect of differences in diameter and number of blades on the power produced. The method used is a simulation method with an artificial wind source. With a wind speed of 8 m/s. The data analysis technique used is 2-way ANOVA using the SPSS application. Variations used are 20 cm and 40 cm in diameter and the number of blades 2 and 4 . The result is a wind turbine with a variation of 40 cm and 4 blades capable of producing the best output which produces 350.98 RPM voltage of 11.64 volts current of 0.144 amperes and power of 1,676 watts. As for BHP, torque, and turbine efficiency with a variation of 40 cm and 4 blades capable of producing the best output where the generated BHP is 3.352 watts, torque 0.091 N / m efficiency 2.17. For the results of calculations with SPSS wind turbines with a diameter variation of 40 cm and 4 blades, the biggest power is 1,744 watts and for BHP produces 3.3520 watts and the efficiency reaches 2.17%. Keyword : Diameter, number of blade, Performance Abstrak Angin adalah sumber energi mekanik yang bisa diperbaharui sehingga dapat dimanfaatkan sebagai sumber energi karena dapat digunakan untuk menggerakkan turbin angin. Turbin angin savonius tipe L merupakan alat untuk mengubah energi angin menjadi listrik dengan konstruksi yang sederhana dan dapat bekerja dengan kecepatan angin yang rendah. Tujuan penelitian ini untuk mengetahui pengaruh perbedaan diameter dan jumlah sudu terhadap unjuk kerja yang dihasilkan. Metode yang digunakan adalah metode simulasi dengan sumber angin buatan. Dengan kecepatan angin 8 m/s. Teknik analisis data yang digunakan adalah ANOVA 2 arah dengan menggunakan aplikasi SPSS. Variasi yang digunakan adalah diameter 20 cm dan 40 cm serta jumlah sudu 2 dan 4. Hasilnya turbin angin dengan variasi 40 cm dan 4 sudu mampu menghasilkan output terbaik yang dimana menghasilkan RPM 350,98 tegangan 11,64 volt arus 0,144 ampere dan daya 1,676 watt. Sedangkan untuk BHP, torsi, dan efisensi turbin dengan variasi 40 cm dan 4 sudu mampu menghasilkan output yang terbaik dimana BHP yang dihasilkan adalah 3,352 watt, torsi 0,091 N/m efisisensi 2,17. Untuk hasil perhitungan dengan SPSS turbin angin dengan variasi diameter 40 cm dan 4 sudu menghasilkan daya terbesar yakni 1,744 watt dan untuk BHP menghasilkan 3,3520 watt dan efisiensinya mencapai 2,17 % untuk torsi tertinggi dicapai turbin variasi 40 cm 2 sudu dengan torsi 0,116.   Kata kunci : diameter, jumlah sudu, unjuk kerja

Aerodynamic Characteristics of Horizontal Axis Wind Turbine With Archimedes Spiral Blade

2013 ◽  
Author(s):  
Kyung Chun Kim ◽  
Yoon Kee Kim ◽  
Ho Seong Ji ◽  
Jook Ho Beak ◽  
Rinus Mieremet
Keyword(s):  
Steady State ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Aerodynamic Characteristics ◽  
Wake Flow ◽  
Power Coefficient ◽  
Horizontal Axis Wind Turbine ◽  
Mean Velocity ◽  
Archimedes Spiral ◽  
Spiral Blade

To investigate the aerodynamic characteristics of an Archimedes spiral wind turbine for urban-usage, both experimental and numerical studies were carried out. The Archimedes spiral blade was designed to produce wind power using drag and lift forces on the blade together. Instantaneous velocity fields were measured by two-dimensional PIV method in the near field of the blade. Mean velocity profiles were compared to those predicted by the steady state and unsteady state CFD simulation. It was found that the interaction between the wake flow at the rotor downstream and the induced velocity due to the tip vortices were strongly affected by the wind speed and resulting rotational speed of the blade. PIV measurements revealed the presence of dominant vertical structures at downstream the hub and near the blade tip. Unsteady CFD simulation results agreed well with those of PIV experiments than the steady state analysis. The power coefficient (Cp) obtained by CFD simulation demonstrated that the new type of wind turbine produced about 0.25, relatively high value compared to other types of urban-usage wind turbine.

scholarly journals Effect of Concentrator, Blade Diameter and Blade Number on the Savonius Wind Turbine Performance

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Ida Bagus Alit ◽  
Rudy Sutanto ◽  
I Made Mara ◽  
Mirmanto Mirmanto
Keyword(s):  
Wind Turbine ◽  
Concentration Ratio ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Wind Speeds ◽  
Vertical Axis Wind Turbines ◽  
Negative Moment ◽  
Low Efficiency ◽  
Low Wind Speeds

Savonius turbine is a type of vertical-axis wind turbines. The turbine has a potential to be developed as it has a simple construction and is suitable for low wind speeds. However, the turbine is still rarely used because of the low efficiency of the turbine compared to other turbines. The low efficiency of the turbine is due to the negative moment. Some efforts have been done to reduce the negative moment such as by adding a wind concentrator. The wind concentrator can steer the incoming wind toward the turbine blades that generate positive moments, consequently, the generated power increases. The aim of this research is to determine the effect of the number and diameter of the Savonius blade wind turbine with an additional concentrator. The concentrator had a concentration ratio of 6:1 and it was tested at the lower wind speeds of 2-5 m/s. The result shows that adding a wind concentrator can increase the rotational speed of the rotor, power coefficient, and the turbine power. The Savonius turbine with two blades has the best performance compared to the three and four blades. The Savonius blade wind turbine with the rotor diameter of 12 cm is the best Savonius turbine for the concentration ratio of 6:1.

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%.

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.

scholarly journals Potential of Shrouded Micro Wind Turbine

2017 ◽  
Vol 7 (2 (S)) ◽  
pp. 340
Author(s):  
Kishor Sontakke ◽  
Samir Deshmukh ◽  
Sandip Patil
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Renewable Energy Sources ◽  
Turbine Blades ◽  
Weather Conditions ◽  
Power Coefficient ◽  
Solar Panels ◽  
Wind Speeds ◽  
Low Wind Speeds

The growing demand for electrical energy for industrial and domestic use, coupled with the limited amount of available fossil fuel reserves and its negative effects on the environment, have made it necessary to seek alternative and renewable energy sources. The use of renewable energy is promoted worldwide to be less dependent on conventional fuels and nuclear energy. Therefore research in the field is motivated to increase efficiency of renewable energy systems. This study aimed to study potential of micro wind turbine and velocity profile through shroud for low wind speeds. Although there is a greater inclination to use solar panels because of the local weather conditions, there are some practical implications that have place the use of solar panels in certain areas to an end. The biggest problem is panel stealing. Also, in some parts of the country the weather is more appropriate to apply wind turbines. Thus, this study paying attention on the design of a new concept to improve wind turbines to be appropriate for the low wind speeds in India. The concept involves the implementation of a concentrator and diffuser to a wind turbine, to increase the power coefficient. Although the wind turbine was not tested for starting speeds, the realization of the shroud should contribute to improved starting of the wind turbine at lower wind speeds. The configuration were not manufactured, but simulated with the use of a program to obtain the power production of the wind turbine over a range of wind speeds. These values were compared to measured results of an open wind turbine developed. The most important topic at hand when dealing with a shrouded wind turbine is to find out if the overall diameter or the blade diameter of the turbine should be the point of reference. As the wind turbine is situated in a shroud that has a larger diameter than the turbine blades, some researchers believe that the overall diameter should be used to calculate the efficiency. The benefits of shrouded wind turbines are discussed.

Analytical and experimental study of the integral aerodynamic characteristics of low-speed wind turbines

2014 ◽  
Vol 118 (1209) ◽  
pp. 1229-1244 ◽  
Author(s):  
M. Valiev ◽  
R. Stepanov ◽  
V. Pakhov ◽  
M. Salakhov ◽  
V. Zherekhov ◽  
...  
Keyword(s):  
Wind Turbines ◽  
Power Efficiency ◽  
Wind Farm ◽  
Aerodynamic Characteristics ◽  
Optimal Conditions ◽  
Low Speed ◽  
Wind Speeds ◽  
Horizontal Axis Wind Turbines ◽  
Low Wind Speeds ◽  
Theoretical Results

Abstract This paper proposes a new wind turbine concept suitable for low-speed winds. The design is studied using a combination of wind-tunnel experimentation and aerodynamic theory. After processing the experimental results, and after comparison with theory, the optimal conditions for the operation of the turbine are identified. Experimental and theoretical results suggest that the design offers a realistic alternative to conventional horizontal axis wind turbines. In addition, the proposed turbine has good power efficiency at low wind speeds, and is suitable for deployment in areas not yet favoured by wind farm developers.

Sign in / Sign up

Export Citation Format

Share Document