Experimental Determination of Optimum Design Configuration for Micro Wind Turbines at Low Wind Speeds

2002 ◽  
Vol 26 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Hideki Tokuyama ◽  
Izumi Ushiyama ◽  
Kazuichi Seki
1964 ◽  
Vol 41 (4) ◽  
pp. 783-792
Author(s):  
JOHN MACHIN

1. The construction and use of a wind-tunnel apparatus is described in which measurements of evaporation under controlled conditions of temperature, humidity and air flow can be made. 2. Two mathematical formulae, applicable to evaporation in relatively low wind speeds, are described. It is suggested that a promising approach to evaporation from moist-skinned animals is provided by the application of Leighly's formula: E = K(p0-pd)c(v/x)n, where the rate of evaporation (E) is expressed in terms of the vapour pressure at the evaporating surface (p0) and in the ambient air (pd), the wind speed (v) and the length of the evaporating surface parallel to the wind (x). The constant, K, is calculated independently and the terms n and c are left for empirical determination. 3. Values of n and c for different types of evaporating surface are given together with the method used in their calculation. Those relating to flat evaporators and to the snail, Helix aspersa, are shown to differ significantly. 4. In general n increases and c decreases as the amount of air disturbance caused by the snail increases. 5. The fact that n for flat surfaces is in good agreement with previously established theory is taken as evidence that Leighly's formula may be validly applied. 6. The combined determination of n and c is introduced as a convenient assessment of a complex form in terms of air flow and evaporation.


2020 ◽  
Vol 1 (2) ◽  
pp. 61-67
Author(s):  
Mohammad Rizqi Saputra ◽  
Nur Kholis ◽  
Mohammad Munib Rosadi

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


2021 ◽  
Vol 104 ◽  
pp. 83-88
Author(s):  
Rahmat Wahyudi ◽  
Diniar Mungil Kurniawati ◽  
Alfian Djafar

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.


2019 ◽  
Vol 141 (11) ◽  
Author(s):  
M. Rafiuddin Ahmed ◽  
Epeli Nabolaniwaqa

The flow characteristics and the lift and drag behavior of a thick trailing-edged airfoil that was provided with fixed trailing-edge flaps (Gurney flaps) of 1–5% height right at the back of the airfoil were studied both experimentally and numerically at different low Reynolds numbers (Re) and angles of attack for possible applications in wind turbines suitable for the wind speeds of 4–6 m/s. The flap considerably improves the suction on the upper surface of the airfoil resulting in a higher lift coefficient. The drag coefficient also increased; however, the increase was less compared with the increase in the lift coefficient, resulting in a higher lift-to-drag ratio in the angles of attack of interest. The results show that trailing-edge flaps can improve the performance of blades designed for low wind speeds and can be directly applied to small wind turbines that are increasingly being used in remote places or in smaller countries.


Author(s):  
Kishor Sontakke ◽  
Samir Deshmukh ◽  
Sandip Patil

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.


2014 ◽  
Vol 118 (1209) ◽  
pp. 1229-1244 ◽  
Author(s):  
M. Valiev ◽  
R. Stepanov ◽  
V. Pakhov ◽  
M. Salakhov ◽  
V. Zherekhov ◽  
...  

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.


2019 ◽  
Vol 12 (2) ◽  
pp. 92
Author(s):  
Susilo Susilo ◽  
Bambang Widodo ◽  
Eva Magdalena Silalahi ◽  
Atmadi Priyono

Bentuk sudu taper linier merupakan bentuk sudu yang paling optimal untuk kecepatan angin yang rendah. Jumlah sudu yang baik untuk kecepatan angin rendah berkisar antara 3-7 buah sudu, namun desain sudu dengan menggunakan airfoil dan profil pada sudut pasang sudu yang bagaimana memberikan daya keluaran dan tegangan keluaran yang optimal. Turbin angin didesain dengan 2 bilah dan 4 bilah dengan sudut pasang yang bisa diatur untuk mendapatkan perbedaan daya optimal masing-masing desain. Pengujian dilakukan di 3 area berbeda untuk mendapatkan gambaran geografis kondisi angin yang berbeda khususnya masalah kecepatan angin di ksiaran 2 m/s - 7 m/s. Pengujian dilakukan dengan luas penampang turbin angin (A) sebesar 3m2 Hasil penelitian menunjukkan bahwa nilai terbaik diperoleh pada kecepatan angin maksimal 4 m/s dan jumlah blade 4  sedangkan untuk nilai terkecil diperoleh pada kecepatan angin 3 m/s dan jumlah blade 2 yaitu. Untuk nilai TSR maksimal pada kecepatan maksimal 4 m/s terjadi pada jumlah blade 4, sedangkan untuk nilai terendah pada kecepatan angin 3 m/s dihasilkan pada jumlah blade 2. Melalui pengukuran berbasis teknologi smart monitoring system, dari penelitian diperoleh semakin tinggi kecepatan angin maka tegangan keluaran semakin tinggi. Semakin tinggi tegangan keluaran, semakin tinggi daya keluaran pada generator. Sudut pasang ? dan jumlah sudu mempengaruhi kecepatan putaran rotor turbin angin. Kecepatan putaran rotor turbin angin berelasi dengan tegangan keluaran generator. pada sudut pasang ? dan jumlah sudu 4, diperoleh daya keluaran yang sebesar 150 watt namun pada kecepatan angin 7 m/s daya turbin yang dihasilkan mencapai 600 watt. Dengan kondisi ini cukup memenuhi untuk alternatif cadangan listrik skala rumah tangga khusunya di pedesaan dan daerah terpencil (rural area). The linear taper blade shape is the most optimal blade shape for low wind speeds. The number of blades that are good for low wind speeds ranges from 3-7 blades, but the blade design uses an airfoil and profile on the blade mounting angle which is how to provide optimal output power and output voltage. Wind turbines are designed with 2 blades and 4 blades with adjustable tide angles to get the difference in the optimal power of each design. Tests were carried out in 3 different areas to obtain a geographical description of different wind conditions, especially the problem of wind speed in the range of 2 m / s - 7 m / s. Tests carried out with a cross section area of  wind turbines (A) of 3m2 The results showed that the best value was obtained at a maximum wind speed of 4 m / s and number 4 blade while the smallest value was obtained at wind speeds of 3 m / s and number 2 blades namely. For the maximum TSR value at a maximum speed of 4 m / s occurs in the number of 4 blades, while for the lowest value at 3 m / s wind speed is produced on the number of blades 2. From the research, the higher the wind speed, the higher the output voltage. The higher the output voltage, the higher the output power at the generator. The ? tide angle and number of blades affect the speed of the wind turbine rotor rotation. The rotational speed of the wind turbine rotor is related to the generator output voltage. at the tide angle ? and number of blades 4, the output power of 150 watts is obtained but with wind speed 7 m/s turbine power 600 watt achieved. With this condition, it is sufficient for alternative household electricity reserves, especially in rural and remote areas (rural areas).


2019 ◽  
Vol 6 (1) ◽  
pp. 64
Author(s):  
Jamal Jamal

Savonius wind turbines are wind turbines that canoperate at low wind speeds, this type of turbine is very suitable tobe used in several places in Indonesia. The research aims toimprove the performance of the Savonius wind turbine withvariations in the number of turbine blades as well as variations inthe velocity of wind speed. The research method wasexperimental where wind turbine testing was carried out withvariations in the number of turbine blades with number of 2, 3and 4 blades, other variations carried out were wind speed at 3.5;4,5; 5.5 and 6.5 m/s. The study results show that the 2-bladeturbine produces greater rotation, but the torque moment islower than the 3 and 4 blade turbines, this can be seen in the lowefficiency of the 2 blade turbine at low wind speeds with highloading. At 3.5 m / s wind turbines 2 blade turbines haveefficiency that tends to be the same as 3 and 4 blade turbines upto 0.5 N but at loads of 0.6 - 1.2 N 2 blade turbines have lowerefficiency, while at wind speeds of 4.5 - 6.5 m / s 2 blade turbineshave greater efficiency than turbines 3 and 4 blades up to a loadof 1.2 N but if the load is added then the efficiency of 2-bladeturbines can be smaller than efficiency 3 and 4-blade.


Author(s):  
Mohammed S. Mayeed ◽  
Adeel Khalid

Today’s wind turbines are designed in a wide range of vertical and horizontal axis types. In this study, several wind turbines are designed for low wind speed areas around the world mainly for domestic energy consumption. The wind speed range of 4–12 mph is considered, which is selected based on the average wind speeds in the Atlanta, GA and surrounding areas. These areas have relatively low average wind speeds compared to various other parts of the United States. Wind energy has been identified as an important source of renewable energy. Traditionally wind energy utilization is limited to areas with higher wind speeds. In reality a lot of areas in the world including Atlanta, GA., have low average wind speeds and demand high energy consumption. In most cases, wind turbines are installed in remote offshore or away from habitat locations, causing heavy investment in installation and maintenance, and loss of energy transfer over long distances. Therefore, the main focus of this study is to extract wind energy domestically at low wind speeds. A few more advantages of small scale wind turbines include reduced visibility, less noise and reduced detrimental environmental effects such as killing of birds, when compared to traditional large turbines. With the latest development in wind turbine technology it is now possible to employ small scale wind turbines that have much smaller foot print and can generate enough energy for small businesses or residential applications. The low speed wind turbines are typically located near residential areas, and are much smaller in sizes compared to the large out of habitat wind turbines. In this study, several designs of wind turbines are modeled using SolidWorks. Virtual aerodynamic analysis is performed using SolidWorks Flow simulation software, and then optimization of the designs is performed based on maximizing the starting rotational torque and acceleration. From flow simulations, forces on the wind turbine blades and structures are calculated, and used in subsequent stress analysis to confirm structural integrity. Critical insight into the low wind speed turbine design is obtained using various configurations and the results are discussed. The study will help identify bottlenecks in the practical and effective utilization of low speed wind energy, and help devise possible remedial plans for the areas around the globe that get low average wind speeds.


2017 ◽  
Vol 138 ◽  
pp. 500-505 ◽  
Author(s):  
Chaianant Sranpat ◽  
Suchaya Unsakul ◽  
Premchai Choljararux ◽  
Thananchai Leephakpreeda

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