Numerical and Experimental Study on Performance Enhancement of Darrieus Vertical Axis Wind Turbine With Wingtip Devices

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Nishant Mishra ◽  
Anand Sagar Gupta ◽  
Jishnav Dawar ◽  
Alok Kumar ◽  
Santanu Mitra
Keyword(s):  
Wind Turbine ◽  
Cfd Simulation ◽  
Performance Enhancement ◽  
Vertical Axis ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Working Parameters

Darrieus type vertical axis wind turbines (VAWT) are being used commercially nowadays; however, they still need to improve in terms of performance as they work in an urban environment where the wind speeds are low and the gusts are frequent. The aerodynamic performance of Darrieus turbine is highly affected by the wingtip vortices. This paper attempts at analyzing and comparing the performance of Darrieus with the use of various wingtip devices. Attempts have also been made to find out optimal working parameters by studying the flow through turbines with different tip speed ratios and different inlet wind speeds. A comparative computational fluid dynamics (CFD) simulation was performed on a small-scale, straight-bladed Darrieus rotor vertical axis wind turbine, with a large stationary domain and a small rotating subdomain using sliding mesh technique. Comparison of the performance of end tip device that can be used against a baseline rotor configuration is done, with the aim of identifying the best tip architecture. The main focus lies on building an experimental setup to validate the results obtained with the CFD simulation and to compare the performance with and without wingtip device. VAWTs with wingtip device show very promising results compared to the baseline model.

Numerical Simulation on Small Scale Straight-Blade and Twisted-Blade Vertical Axis Wind Turbine

2012 ◽  
Vol 455-456 ◽  
pp. 334-338
Author(s):  
Yong Zhe Lv ◽  
Dong Xiang Jiang ◽  
Yong Jiang
Keyword(s):  
Wind Turbine ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Straight Blade ◽  
Fluid Field ◽  
Solid Models ◽  
Computational Fluid Dynamics Cfd ◽  
Twisted Blade

This paper presents an analysis on the performance of vertical axis wind turbine of two types, namely straight-blade vertical axis wind turbine (SB-VAWT) and twisted-blade vertical axis wind turbine (TB-VAWT). An attempt of this simulation is to identify which type performs better in the same wind conditions and swept area. Three-dimensional computational fluid dynamics (CFD) was adopted in this analysis, after solid models of them were generated. Preliminary results of torque, power and aerodynamics in the fluid field were obtained for discussion. Finally, there provided some guidance for future wind tunnel tests.

scholarly journals Numerical investigation of the effect of triangle strut in vertical axis wind turbine (VAWT)

2020 ◽  
Vol 11 (2) ◽  
pp. 95
Author(s):  
Tri Admono ◽  
Yoyon Ahmudiarto ◽  
Amma Muliya Romadoni ◽  
Iman Abdurahman ◽  
Agus Salim ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Simulation Method ◽  
Wind Flow ◽  
Vertical Axis Wind Turbine ◽  
Pressure Losses ◽  
Multi Stage ◽  
Computational Fluid Dynamics Cfd

Strut is used in vertical axis wind turbine (VAWT) to restraint the framework. In this study, struts are analyzed to show the pressure losses in VAWT. ANSYS computational fluid dynamics (CFD) software is used to investigate triangle strut in VAWT. This study aims to show a CFD simulation of struts, which affects the aerodynamic of VAWT. In CFD software, the aerodynamic of VAWT can be analyzed in terms of pressure losses in the struts. The simulation method starts by making a struts model, then meshing and setting up ANSYS's boundary conditions. The last iteration runs in ANSYS until convergence. Our results show the percentage of pressure losses with the variation of the angle of wind 0°, 20°, 40°, and 60° are 0.67 %, 0.52 %, 0.48 %, and 0.52 %. The effect of triangle strut in VAWT did not affect the wind flow to the VAWT blade. The results also indicated that the triangle strut could be applied in the multi-stage of VAWT system.

scholarly journals Numerical evaluation of aerodynamic performances of vertical-axis wind turbine rotor with flow concentrator

2020 ◽  
Author(s):  
Jelena Svorcan ◽  
◽  
Ognjen Peković ◽  
Toni Ivanov ◽  
Miloš Vorkapić ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Turbine Rotor ◽  
Operating Conditions ◽  
Power Coefficient ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Flow Simulations ◽  
Wind Speeds

With wind energy extraction constantly increasing, the interest in small-scale urban wind turbines is also expanding. Given that these machines often work in adverse operating conditions (Earth’s boundary layer, vortex trails of surrounding objects, small and changeable wind speeds), additional elements that locally augment wind velocity and facilitate turbine start may be installed. This paper investigates possible benefits of adding an optimized flow concentrator to a vertical-axis wind turbine (VAWT) rotor. Three-dimensional, unsteady, turbulent, incompressible flow simulations of both isolated rotor consisting of three straight blades and a rotor with flow concentrator have been performed in ANSYS FLUENT by finite volume method for several different operational regimes. This type of flow simulations is challenging since flow angles are high, numerous flow phenomena and instabilities are present and the interaction between the blades and detached vortices can be significant. The rotational motion of the blades is solved by the unsteady Sliding Mesh (SM) approach. Flow field is modeled by Unsteady Reynolds Averaged Navier-Stokes (URANS) equations with k-ω SST turbulence model used for closure. Both quantitative and qualitative examinations of the obtained numerical results are presented. In particular, the two computed power coefficient curves are compared and the advantages of installing a flow concentrator are accentuated.

scholarly journals Investigation on the Performance of a Portable Power Generation System with a Low-Cost Vertical Axis Wind Turbine

2021 ◽  
Vol 11 (6) ◽  
pp. 7809-7813
Author(s):  
M. F. Basar ◽  
A. M. Norazizi ◽  
I. Mustaffa ◽  
C. T. Colin ◽  
S. N. S. Mirin ◽  
...  
Keyword(s):  
Power Generation ◽  
Wind Speed ◽  
Wind Turbine ◽  
Low Cost ◽  
Public Awareness ◽  
Vertical Axis ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Wind Speeds ◽  
Portable Power

The purpose of this project was to develop an innovative, small-scale, and portable vertical axis wind turbine for power generation. The wind turbine was simple in design and economical. Wind speeds ranging from 2.0ms-1 to 7.0ms-1 were tested on the proposed wind turbine. The experiments revealed that the turbine required a minimum wind speed of 3.9ms-1 to operate. According to the results, the proposed turbine achieved its maximum power output of 5.6W at a rotational speed of 65rpm when the wind speed was 7.0m/s. Additionally, voltage and current increased proportionately with increasing wind speed. The proposed system showed an average coefficient factor between 0.10 and 0.12. This portable wind turbine potentially revolutionizes industry while raising public awareness about clean and renewable energy.

Performance enhancement of Savonius wind turbine by blade shape and twisted angle modifications

2021 ◽  
pp. 095765092098794
Author(s):  
Ahmed M Nagib Elmekawy ◽  
Hassan A Hassan Saeed ◽  
Sadek Z Kassab
Keyword(s):  
Wind Turbine ◽  
Performance Enhancement ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Vertical Axis ◽  
Cfd Simulations ◽  
Sliding Mesh ◽  
Blade Shape ◽  
Rotor Shape ◽  
Twisting Angle

Three-dimensional CFD simulations are carried out to study the increase of power generated from Savonius vertical axis wind turbines by modifying the blade shape and blade angel of twist. Twisting angle of the classical blade are varied and several proposed novel blade shapes are introduced to enhance the performance of the wind turbine. CFD simulations have been performed using sliding mesh technique of ANSYS software. Four turbulence models; realizable k -[Formula: see text], standard k - [Formula: see text], SST transition and SST k -[Formula: see text] are utilized in the simulations. The blade twisting angle has been modified for the proposed dimensions and wind speed. The introduced novel blade increased the power generated compared to the classical shapes. The two proposed novel blades achieved better power coefficients. One of the proposed models achieved an increase of 31% and the other one achieved 32.2% when compared to the classical rotor shape. The optimum twist angel for the two proposed models achieved 5.66% and 5.69% when compared with zero angle of twist.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

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