scholarly journals The effect of Rotor Separation on the Performance of a Dual Rotor Wind Turbine

2021 ◽  
Author(s):  
ANTHONY ADEYANJU ◽  
Omar Mohammed ◽  
Krishpersad Manohar
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
High Energy ◽  
Separation Distance ◽  
Energy Output ◽  
Power Coefficient ◽  
Total Power ◽  
Speed Ratio ◽  
Horizontal Axis Wind Turbine ◽  
Tip Speed Ratio

This study conducted simulation and experimental analysis on a dual rotor horizontal axis wind turbine to determine the effect of rotor separation on its performance. An air study was conducted to optimize the turbine blades to a local climate of Trinidad, it was determined that a NACA 64-315 air foil would be the most optimum for the conditions. QBlade software was used for the simulation, the power flow performance for multiple iterations of wind speed was found for the design. The effect of rotor separation on the performance of the dual rotor wind turbine was studied with rotor separation 0.25 m to 3.0 m at an interval of 0.25 m and it was discovered that the smallest rotor separation 0.25 m shows the largest tip speed ratio, while the largest rotor separation distance 3m has the smallest tip speed ratio at a fan speed of 1m/s. Also, as the rotor separation decreases the power coefficient (C P ) and the total power increase, which resulted to high energy output of the DRHAWT. This result is valid for the QBlade simulations and the experimental results.

scholarly journals Effectiveness of Nature-Inspired Algorithms using ANFIS for Blade Design Optimization and Wind Turbine Efficiency

Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 456 ◽  
Author(s):  
Md. Sarkar ◽  
Sabariah Julai ◽  
Chong Wen Tong ◽  
Siti Toha
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Power Coefficient ◽  
Design Parameters ◽  
Speed Ratio ◽  
Blade Design ◽  
Horizontal Axis Wind Turbine ◽  
Bee Colony ◽  
Maximum Value ◽  
Nature Inspired Algorithms

Blade design of the horizontal axis wind turbine (HAWT) is an important parameter that determines the reliability and efficiency of a wind turbine. It is important to optimize the capture of the energy in the wind that can be correlated to the power coefficient ( C p ) of HAWT system. In this paper, nature-inspired algorithms, e.g., ant colony optimization (ACO), artificial bee colony (ABC), and particle swarm optimization (PSO) are used to search for the blade parameters that can give the maximum value of C p for HAWT. The parameters are tip speed ratio, blade radius, lift to drag ratio, solidity ratio, and chord length. The performance of these three algorithms in obtaining the optimal blade design based on the C p are investigated and compared. In addition, an adaptive neuro-fuzzy interface (ANFIS) approach is implemented to predict the C p of wind turbine blades for investigation of algorithm performance based on the coefficient determination (R2) and root mean square error (RMSE). The optimized blade design parameters are validated with experimental results from the National Renewable Energy Laboratory (NREL). It was found that the optimized blade design parameters were obtained using an ABC algorithm with the maximum value power coefficient higher than ACO and PSO. The predicted C p using ANFIS-ABC also outperformed the ANFIS-ACO and ANFIS-PSO. The difference between optimized and predicted is very small which implies the effectiveness of nature-inspired algorithms in this application. In addition, the value of RMSE and R2 of the ABC-ANFIS algorithm were lower (indicating that the result obtained is more accurate) than the ACO and PSO algorithms.

Aerodynamic Optimization of a Swept Horizontal Axis Wind Turbine Blade

2021 ◽  
pp. 1-28
Author(s):  
Mehmet Numan Kaya ◽  
Faruk Köse ◽  
Oguz Uzol ◽  
Derek Ingham ◽  
Lin Ma ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Turbine Blade ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Design Parameters ◽  
Speed Ratio ◽  
Blade Design ◽  
Horizontal Axis Wind Turbine ◽  
Tip Speed Ratio

Abstract The aerodynamic shapes of the blades are still of high importance and various aerodynamic designs have been developed in order to increase the amount of energy production. In this study, a swept horizontal axis wind turbine blade has been optimized to increase the aerodynamic efficiency using the Computational Fluid Dynamics method. To illustrate the technique, a wind turbine with a rotor diameter of 0.94 m has been used as the baseline turbine and the most appropriate swept blade design parameters, namely the sweep start up section, tip displacement and mode of the sweep have been investigated to obtain the maximum power coefficient at the design tip speed ratio. At this stage, a new equation that allows all three swept blade design parameters to be changed independently has been used to design swept blades, and the response surface method has been used to find out the optimum swept blade parameters. According to the results obtained, a significant increase of 4.28% in the power coefficient was achieved at the design tip speed ratio with the new designed optimum swept wind turbine blade. Finally, baseline and optimum swept blades have been compared in terms of power coefficients at different tip speed ratios, force distributions, pressure distributions and tip vortices.

scholarly journals Design and optimization of a small horizontal axis wind turbine using BEM theory and tip loss corrections

2021 ◽  
Vol 294 ◽  
pp. 01003
Author(s):  
Somaya Younoussi ◽  
Abdeslem Ettaouil
Keyword(s):  
Wind Turbine ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Optimization Approach ◽  
Horizontal Axis Wind Turbine ◽  
Newton’S Iterative Method ◽  
Tip Speed Ratio ◽  
De Vries ◽  
Bem Theory

In this paper, an optimization approach of a small horizontal axis wind turbine based on BEM theory including De Vries and Shen et al. tip loss corrections is proposed. The optimal blade geometry was obtained by maximizing the power coefficient along the blade using the optimal angle of attack and the optimal tip speed ratio. The Newton’s iterative method applied to axial induction factor was used to solve the problem. This study was conducted for a NACA4418 small wind turbine, at low wind velocity. Among the two used tip loss corrections, the De Vries correction was found to be the most suitable for this blade optimization method. The optimal design was obtained for a tip speed ratio of 5 and has recorded a power coefficient equal to 0.463.

scholarly journals Performance assessment and optimization of a helical Savonius wind turbine by modifying the Bach’s section

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
M. Niyat Zadeh ◽  
M. Pourfallah ◽  
S. Safari Sabet ◽  
M. Gholinia ◽  
S. Mouloodi ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Performance Assessment ◽  
Turbulent Flows ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
Basic Model ◽  
Turbine Performance ◽  
Primary Model ◽  
Savonius Wind Turbine

AbstractIn this paper, we attempted to measure the effect of Bach’s section, which presents a high-power coefficient in the standard Savonius model, on the performance of the helical Savonius wind turbine, by observing the parameters affecting turbine performance. Assessment methods based on the tip speed ratio, torque variation, flow field characterizations, and the power coefficient are performed. The present issue was stimulated using the turbulence model SST (k- ω) at 6, 8, and 10 m/s wind flow velocities via COMSOL software. Numerical simulation was validated employing previous articles. Outputs demonstrate that Bach-primary and Bach-developed wind turbine models have less flow separation at the spoke-end than the simple helical Savonius model, ultimately improving wind turbines’ total performance and reducing spoke-dynamic loads. Compared with the basic model, the Bach-developed model shows an 18.3% performance improvement in the maximum power coefficient. Bach’s primary model also offers a 12.4% increase in power production than the initial model’s best performance. Furthermore, the results indicate that changing the geometric parameters of the Bach model at high velocities (in turbulent flows) does not significantly affect improving performance.

Numerical Research on the Characteristics of Lift-Drag Type Vertical Axis Wind Turbine

2012 ◽  
Vol 189 ◽  
pp. 448-452
Author(s):  
Yan Jun Chen ◽  
Guo Qing Wu ◽  
Yang Cao ◽  
Dian Gui Huang ◽  
Qin Wang ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Chord Length ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Tip Speed Ratio ◽  
Middle Range ◽  
Parabolic Form ◽  
Cfd Method

Numerical studies are conducted to research the performance of a kind of lift-drag type vertical axis wind turbine (VAWT) affected by solidity with the CFD method. Moving mesh technique is used to construct the model. The Spalart-Allmaras one equation turbulent model and the implicit coupled algorithm based on pressure are selected to solve the transient equations. In this research, how the tip speed ratio and the solidity of blade affect the power coefficient (Cp) of the small H-VAWT is analyzed. The results indicate that Cp curves exhibit approximate parabolic form with its maximum in the middle range of tip speed ratio. The two-blade wind turbine has the lowest Cp while the three-blade one is more powerful and the four-blade one brings the highest power. With the certain number of blades, there is a best chord length, and too long or too short chord length may reduce the Cp.

scholarly journals Investigation of an Innovative Rotor Modification for a Small-Scale Horizontal Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2649 ◽  
Author(s):  
Artur Bugała ◽  
Olga Roszyk
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Airflow Distribution

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.

Study on Performance and Flow Condition of a Cross-Flow Wind Turbine With a Symmetrical Casing

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Junichiro Fukutomi ◽  
Toru Shigemitsu ◽  
Hiroki Daito
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Flow Condition ◽  
Cross Flow ◽  
Low Noise ◽  
Maximum Power ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
The Cross

A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10%) as compared to that of other small wind turbines. Prevailing winds in two directions often blow in urban and coastal regions. Therefore, in order to improve the performance and the flow condition of the cross-flow rotor, a casing suitable for this sort of prevailing wind conditions is designed in this research and the effect of the casing is investigated by experimental and numerical analysis. In the experiment, a wind tunnel with a square discharge is used and main flow velocity is set as 20 m/s. A torque meter, a rotational speed pickup, and a motor are assembled with the same axis as the test wind turbine and the tip speed ratio is changeable by a rotational speed controller. The casing is set around the cross-flow rotor and flow distribution at the rotor inlet and the outlet is measured by a one-hole pitot tube. The maximum power coefficient is obtained as Cpmax = 0.19 with the casing, however Cpmax = 0.098 without the casing. It is clear that the inlet and the outlet flow condition is improved by the casing. In the present paper, in order to improve the performance of a cross-flow wind turbine, a symmetrical casing suitable for prevailing winds in two directions is proposed. Then, the performance and the internal flow condition of the cross-flow wind turbine with the casing are clarified. Furthermore, the influence of the symmetrical casing on performance is discussed and the relation between the flow condition and performance is considered.

scholarly journals Numerical simulation and experimental study of blade pitch effect on Darrieus straight-bladed wind turbine with high solidity: A case study under realistic conditions

2020 ◽  
Author(s):  
Milad Babadi Soultanzadeh ◽  
Alireza Moradi
Keyword(s):  
Wind Turbine ◽  
Numerical Method ◽  
Pitch Angle ◽  
Numerical Results ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Regulation System ◽  
Lower Velocity ◽  
Realistic Condition ◽  
Tip Speed Ratio

Abstract Numerical and experimental studies were performed to examined the influence of pitch angle on the aerodynamic performance of a small Darrieus straight blade vertical axis wind turbine with high solidity and pitch regulation system under a realistic condition. By comparing experimental and numerical results, numerical results were validated. The power coefficient was measured and calculated at different tip speed ratios and for two pitch angles 0 and 5. The results revealed that 5 degrees increase in the pitch angle led to 25% elevation in the maximum value of the power coefficient (performance coefficient). Also, the numerical results showed higher accuracy at lower tip speed ratios for both pitch angles. After numerical method validation, numerical method employed to calculate the coefficient of performance and coefficient of torque function of Azimuth position as well as the flow field in the rotor affected zone and lateral distance. According to the numerical results, vorticity generation increased by the rise in the pitch angle at a constant tip speed ratio; the maximum performance coefficient occurred at a lower tip speed ratio with elevation in the pitch angle; finally, the increment in the pitch angle led to lower velocity profile in lateral distances of the rotor.

scholarly journals STUDI EKSPERIMEN TEKNOLOGI PEMBANGKIT LISTRIK TENAGA ARUS LAUT (PLTAL) MENGGUNAKAN SAVONIUS BACH ROTOR

2019 ◽  
Vol 16 (2) ◽  
pp. 75
Author(s):  
Yusiran Hikmat ◽  
Erwin Erwin
Keyword(s):  
Output Power ◽  
Turbine Blades ◽  
Ocean Currents ◽  
Ocean Current ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
Power Generation System ◽  
Generator Output ◽  
Turbine Output

Design and experiment of ocean current power generation system have been carried out using the Bach Savonius rotor. In this research, the influence of the velocity of ocean currents, the number of turbine blades, and the blade arc angle of the generator output power are studied. The results showed that the turbine output power is strongly influenced by the velocity of ocean currents where the velocity values of ocean currents varied in the range 0,63-1,98 m/sec. The maximum elctrical power of the turbine occurs at a current velocity of 1,98 m/sec of 26,88 Watts. The number of turbine blades has a significant effect on turbine output power. The turbine reaches maximum power is found in the rotor with a number of 3 blades with a power coefficient of 0,1176 on the tip speed ratio of 0,359. The blade arc angle is varied at angles of 90˚, 135˚ and 165˚. The blade arc angle 135˚ gives the best performance with a power coefficient of 0,102 on the tip speed ratio of 0,298.

scholarly journals PENGARUH JUMLAH BLADE DAN VARIASI PANJANG CHORD TERHADAP PERFORMANSI TURBIN ANGIN SUMBU HORIZONTAL (TASH)

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
I Kade Wiratama ◽  
Made Mara ◽  
L. Edsona Furqan Prina
Keyword(s):  
Wind Turbine ◽  
Energy Use ◽  
Electrical Energy ◽  
Vertical Axis ◽  
Energy System ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine

The willingness of electrical energy is one energy system has a very important role in the economic development of a country's survival. As one energy source (wind) can be converted into electrical energy with the use of a horizontal axis wind turbine. Wind Energy Conversion Systems (WECS) that we know are two wind turbines in general, ie the horizontal axis wind turbine and vertical axis wind turbine is one type of renewable energy use wind as an energy generator. The purpose of this study was to determine the effect of the number of blade and the radius chord of rotation (n), Torque (T), Turbine Power (P), Power Coefficient (CP) and Tip Speed Ratio (λ) generated by the horizontal axis wind turbine with form linear taper. The results show that by at the maximum radius of the chord R3 the number blade 4 is at rotation = 302.700 rpm, Pturbine = 7.765 watt, Torque = 0.245 Nm, λ = 3.168 and Cp = 0.403 or 40.3%.

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