scholarly journals Analysis of the Behavior in the Wind Tunnel of an Experimental Model of Savonius with Interlocking Cups with the Classic Ones with 2, 3 and 4 Semi-Cylindrical Cups

2021 ◽  
Vol 44 (1) ◽  
pp. 11-18
Author(s):  
Nelu CAZACU
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Experimental Model ◽  
Experimental Models ◽  
Dead Zones ◽  
Wind Speeds ◽  
Measuring Section ◽  
Formed Channel ◽  
Low Wind Speeds ◽  
Air Passage

The paper is based on experiments conducted on the wind tunnel at low wind speeds (<9.5 m/s), on an experimental model of S-rotor wind turbine type with four blades and a D/H ratio of 1. Semi-cylindrical cups opposite 180 degrees are aerodynamically coupled by overlap and with an air passage gap to equalize the pressures. The formed channel is shaped to allow the same for pairs of blades at 90 degrees. The experimental model has an area of 0.025 m2 which represents 10% of the surface of the measuring section of the wind tunnel (0.25 m2). The behavior of the experimental model was compared with the experimental models of S-rotor with 2, 3 and 4 semi-cylindrical cups, with the same interception surface. The results confirm the better start of the experimental model by reducing dead zones and operating more evenly and stably over a longer range of wind speeds. The results confirm the validity of the proposed concept of interwoven aerodynamic coupling of semi-cylindrical cups.

Design and Testing of Low-Speed Wind Turbine Blade

2009 ◽  
Author(s):  
R. S. Amano ◽  
R. J. Malloy
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Pid Controller ◽  
Current Data ◽  
Potential Candidate ◽  
Efficient Energy ◽  
Wind Speeds ◽  
Tunnel Model ◽  
Low Wind Speeds ◽  
Design And Testing

There is a need for clean, cheap, and efficient energy. One potential candidate for a source of this energy is a wind energy. In order to maximize the amount of energy captured, a new, low airspeed wind turbines must be designed. A wind turbine was created using the NACA 4412 foil shape and a decreasing chord length with increasing distance from the center of the turbine. The angle of attack was also varied. The airfoil was analyzed in CFD and tested via wind tunnel model. The turbine was connected to a motor which was connected to a resistor and current and voltage meters. Using the voltage and current data at a prescribed rate of rotation, the power generated was calculated. Despite the shortcomings of the model, decent power output was generated. Since the wind tunnel could only perform up to 5 ft/s (or 3.4 mph), this shows that the turbine is acceptable for low wind speeds. For practical use the turbine would need to be scaled to a greater size and a PID controller that can generate higher resistance would need to be employed.

The Influence of the Number of Semi-Cycindrical Cups on the Behavior of an Experimental Model of Vertical Axis Wind Turbine at Low Wind Speed and no Load

2020 ◽  
Vol 43 (3) ◽  
pp. 43-53
Author(s):  
Nelu CAZACU ◽  
◽  
◽  
Keyword(s):  
Wind Tunnel ◽  
Experimental Model ◽  
Vertical Axis ◽  
Experimental Models ◽  
Vertical Axis Wind Turbine ◽  
Cross Sectional ◽  
Wind Speeds ◽  
Low Wind Speed ◽  
Cylindrical Cup ◽  
Electrical Loads

The work is based on experiments made in the wind tunnel on experimental models of Savonius type wind turbines with blades in the shape of a semicylindrical cup. The number of blades changes: 2, 3, 4, 5 and 6. The experimental model allows the addition / removal of blades in the form of a semi-cylindrical cup followed by static balancing. The wind tunnel used has the measuring area 0.5 mx0.5 m and the length of 1.25 m and the experimental models have the interception surface at a maximum value of 10% of the cross-sectional area of the wind tunnel (diameter 158 mm and height 158 mm). The experiments were performed at wind speeds between 0...9.7 m/s between peaks and no (mechanical and / or electrical) loads. The results confirm the influence of the number of semi-cylindrical cups on the rotational speed and other factors over experimental model of Savonius type turbines in no load conditions.

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%.

scholarly journals Optimal Control of the Positional Electric Drive and Its Implementation

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 70
Author(s):  
Vladimir Dotsenko ◽  
Roman Prokudin ◽  
Alexander Litvinenko
Keyword(s):  
Optimal Control ◽  
Wind Turbine ◽  
Electric Drive ◽  
Minimum Energy ◽  
Air Gap ◽  
Synchronous Generators ◽  
Capacitor Discharge ◽  
Wind Speeds ◽  
Minimum Energy Consumption ◽  
Low Wind Speeds

The article deals with the optimal control of the positional electric drive of the stator element of a segment-type wind turbine. The calculation options charts current in the assumption of the minimum energy consumption and the implementation of line chart current using the phenomenon of capacitor discharge. The analysis of the implementation is expressed in a jump-like change in current and a triangular graph of the speed change. This article deals with small capacity synchronous wind turbine generators with a segment type stator. These units have the possibility of intentionally changing the air gap between the rotor and stator. This allows: (1) Reduce the starting torque on the rotor shaft, which will allow the rotor to pick up at low wind speeds. (2) Equivalent to change of air gap in this case is change of excitation of synchronous generators. Thus, the purpose of the article is to consider a method of excitation of generators in a segmented design, by controlling the gap with the electric drive, while providing control should be carried out with minimal losses.

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

Effect of Slotted Angle on Savonius Wind Turbine Performance

2021 ◽  
Vol 104 ◽  
pp. 83-88
Author(s):  
Rahmat Wahyudi ◽  
Diniar Mungil Kurniawati ◽  
Alfian Djafar
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Electrical Energy ◽  
Speed Ratio ◽  
Angle Variation ◽  
Wind Speeds ◽  
Turbine Performance ◽  
Savonius Wind Turbine ◽  
Low Wind Speeds

The potential of wind energy is very abundant but its utilization is still low. The effort to utilize wind energy is to utilize wind energy into electrical energy using wind turbines. Savonius wind turbines have a very simple shape and construction, are inexpensive, and can be used at low wind speeds. This research aims to determine the effect of the slot angle on the slotted blades configuration on the performance produced by Savonius wind turbines. Slot angle variations used are 5o ,10o , and 15o with slotted blades 30% at wind speeds of 2,23 m/s to 4,7 m/s using wind tunnel. The result showed that a small slot angle variation of 5o produced better wind turbine performance compared to a standard blade at low wind speeds and a low tip speed ratio.

Backstepping control of a wind turbine for low wind speeds

2016 ◽  
Vol 84 (4) ◽  
pp. 2435-2445 ◽  
Author(s):  
Abderrahmen Mechter ◽  
Karim Kemih ◽  
Malek Ghanes
Keyword(s):  
Wind Turbine ◽  
Backstepping Control ◽  
Wind Speeds ◽  
Low Wind Speeds

Experimental and Numerical Assessment of Cross Flow Vertical Axis Wind Turbine

2019 ◽  
Author(s):  
Sivamani Seralathan ◽  
Micha Premkumar Thomai ◽  
Rian Leevinson Jayakumar ◽  
Basireddy Venkata Lokesh Reddy ◽  
Hariram Venkatesan
Keyword(s):  
Wind Turbine ◽  
Renewable Energy Sources ◽  
Cross Flow ◽  
Experimental Investigations ◽  
Speed Ratio ◽  
Positive Interaction ◽  
Polar Plot ◽  
Tip Speed Ratio ◽  
Wind Speeds ◽  
Low Wind Speeds

Abstract Due to increase in energy demand along with environmental awareness, the attention is shifting towards renewable energy sources. A wind turbine developed from Banki water turbine is used in this study as it starts at low-wind speeds and has high starting torque. Experimental investigations are carried out on a test rig equipped with open jet wind tunnel with wind velocity varying from 7 to 11 m/s. Later, 3D steady-state numerical analyses are performed using ANSYS CFX for better understanding of the flow physics of cross flow VAWT. The experimental investigations revealed that cross flow VAWT has a good self-starting ability at relatively low-wind speeds. A peak power coefficient (Cp, max) value of 0.059 is observed for the tip speed ratio (λ) of 0.30. As the tip speed ratio is raised further, the Cp value is observed to decrease gradually. The numerical simulations reveal the reason for the drop in Cp value. This is due to lessening of positive interaction between the flow and cross flow VAWT blades at higher λ due to vortex formation. The torque coefficient is found to decrease almost linearly from a peak value of around 0.49 at λ = 0 to a value of 0 around λ = 0.60. Polar plot between angle and torque shows that torque output of the turbine is nearly same in all directions which reinforce the potency of cross flow VAWT to be omni-directional as it produces the same performance regardless of wind directions.

Short-Term Fatigue Analysis of Semi-Submersible Wind Turbine Tower

2011 ◽  
Author(s):  
Marit I. Kvittem ◽  
Torgeir Moan ◽  
Zhen Gao ◽  
Chenyu Luan
Keyword(s):  
Wind Turbine ◽  
Fatigue Damage ◽  
Time Domain ◽  
Narrow Band ◽  
Response Spectra ◽  
Spectral Density Function ◽  
Mean Value ◽  
Short Term ◽  
Wind Speeds ◽  
Low Wind Speeds

Coupled time domain analyses of a semi-submersible wind turbine are performed with the intention to study motions affecting fatigue damage at the base of the tower. The software applied is SIMO/RIFLEX with the extension TDHmill, which gives the wind thrust force and gyro moment on the wind turbine as point loads in the tower top. Short term environmental conditions are chosen from a joint wind and wave distribution for a site in the Northern North Sea. Variance spectra, mean value, standard deviation, kurtosis, skewness and Vanmarcke’s bandwidth parameter are calculated for stresses at the base of the tower. Damage is calculated for each short term condition by two methods; rainflow counting and narrow band approximation. The accuracy of narrow band approximation estimates for fatigue are examined for the structure in question. Time domain simulations are carried out for different sea states and fatigue damage is calculated for each case. Simulations show that turbulent wind dominates the response at low wind speeds and the response spectral density function tends to be very wide-banded. For wave dominated response, spectra have lower bandwidth, and narrow banded approximation for fatigue damage gives estimates 20–50% above rainflow counted damage.

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