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.

Numerical Study to Quantify the Effects of Struts and Central Hub on the Performance of a Three Dimensional Vertical Axis Wind Turbine Using Sliding Mesh

2013 ◽  
Author(s):  
M. Salman Siddiqui ◽  
Naveed Durrani ◽  
Imran Akhtar
Keyword(s):  
Wind Turbine ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Unit Length ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Torque Ripple ◽  
Outer Diameter ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh

A computational fluid dynamic (CFD) analysis is carried out to investigate the effects of struts and central hub in 3D on the overall performance prediction of a three dimensional vertical axis wind turbine (VAWT) with three Darrieus H-type blades. The VAWT has the outer diameter of 2.5m and finite unit length height with expected output of 2KVA. This type of small VAWT are expected to perform better on roof tops of the built-up urban area. The analysis is carried out using sliding mesh concept in commercial CFD software ‘Ansys Fluent 13’. It is observed that the struts and central hub assembly induce additional drag and generate strong vortices which caused a substantial decrease in the performance parameters of the turbine. The numerical simulation are carried out over a three dimensional VAWT with and without struts and central hub. It is found that both the cases show a similar trend of the torque ripple for any one blade while for the upstream path, on the contrary the blades experience a drop in performance from 220° to 360° due to the struts and central hub assembly. A detailed comparative analysis between both the cases is made over the TSR values range from 1.5 to 4.5. At TSR = 1.5, the performance coefficient of the cases with and without struts and central hub are same. However, for the case of struts and central hub, TSR 4 and above show negative values of power coefficients.

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 Study of Pitch Angle on H-Type Vertical Axis Wind Turbine

2012 ◽  
Vol 499 ◽  
pp. 259-264
Author(s):  
Qi Yao ◽  
Ying Xue Yao ◽  
Liang Zhou ◽  
S.Y. Zheng
Keyword(s):  
Wind Turbine ◽  
Pitch Angle ◽  
Numerical Study ◽  
Vertical Axis ◽  
Azimuth Angle ◽  
Power Coefficient ◽  
Cfd Model ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh ◽  
Mesh Technique

This paper presents a simulation study of an H-type vertical axis wind turbine. Two dimensional CFD model using sliding mesh technique was generated to help understand aerodynamics performance of this wind turbine. The effect of the pith angle on H-type vertical axis wind turbine was studied based on the computational model. As a result, this wind turbine could get the maximum power coefficient when pitch angle adjusted to a suited angle, furthermore, the effects of pitch angle and azimuth angle on single blade were investigated. The results will provide theoretical supports on study of variable pitch of wind turbine.

scholarly journals Three-Dimensional Wind Field Construction and Wind Turbine Siting in an Urban Environment

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 137 ◽  
Author(s):  
Mingrui Liu ◽  
Xiuling Wang
Keyword(s):  
Wind Turbine ◽  
Urban Environment ◽  
Wind Field ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Urban Environments ◽  
Urban Region ◽  
Wind Flow ◽  
Simulation Results

Three-dimensional urban wind field construction plays an important role not only in the analysis of pedestrian levels of comfort but also in the effectiveness of harnessing wind energy in an urban environment. However, it is challenging to accurately simulate urban wind flow due to the complex land use in urban environments. In this study, a three-dimensional numerical model was developed for urban wind flow construction. To obtain an accurate urban wind field, various turbulence models, including the Reynolds stress model (RSM), k-ω shear stress transport (SST), realizable k-ε, and (Re-Normalisation Group (RNG) k-ε models were tested. Simulation results were compared with experimental data in the literature. The RSM model showed promising potential in simulating urban wind flow. The model was then adopted to simulate urban wind flow for Purdue University Northwest, which is located in the Northwest Indiana urban region. Based on the simulation results, the optimal location was identified for urban wind turbine siting.

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