2-D Numerical Simulation of Vertical Axis Wind Turbine for Performance Enhancement

Document Type : Original Article


1 Master of Science, Department of Renewable Energy and Environment, Faculty of New Sciences and Technologies, University of Tehran, Iran

2 Associate Professor, Faculty of New Sciences and Technologies, University of Tehran, Iran


Due to its availability, high efficiency, and low cost, wind energy plays a critical role in the transition from energy sources to renewable sources in order to achieve sustainable development. In many villages of Iran where the required electricity does not exceed a few kilowatts and relatively good wind potential exists in different seasons of the year, the application of micro wind turbines as an off-grid source for supplying electricity to these areas can be effective in reducing greenhouse gas emissions and diminish the usage of thermal power plants. numerical and computational methods are able to evaluate the performance of wind turbines while reducing the cost of fabrication and testing required and provide the opportunity for optimizing the geometry and design of turbine with higher efficiencies.. To this end, this study has utilized the computational fluid dynamics analysis to predict and improve the performance of a high-solidity vertical axis wind turbine.
Materials and methods
The present study proposes a numerical simulation in Ansys 18 (commercial software), based on Computational Fluid dynamics (CFD) to predict the performance of a high-solidity, 3-blade, low-speed vertical axis wind turbine. In this regard, a two-dimensional fluid domain was generated, and a detailed meshing and a comprehensive mesh study were carried out. Various turbulence models were investigated and among them the Transition SST turbulence model showed the most acceptable results. Subsequently, other items including the boundary conditions, solver type, and time step were selected and optimized. To achieve a reliable solution to the problem and reduce the errors in the results, simulations were performed for 5 turbine rotation cycles.
Discussion and conclusions
Based on the results, The minimum and maximum torque of the turbine per unit length for 4th and 5th revolutions are -15.03 Nm and 45.33 Nm and the average is 10.80 N. The power coefficient and the output power of the turbine rises as the tip speed ratio (turbine rotational speed) increases, reaches its maximum value and then decreases. In order to validate the simulation results, respective curves based on simulation and experimental data are provided and the amount of deviations are investigated. Following the model’s results, The maximum turbine power coefficient is 0.29 at a blade tip speed ratio of 1.62, while laboratory data reports these values as 0.253 and 1.58. therefore, there is a 23.40% difference between experimental and model results in the maximum power coefficient. Moreover, the peak turbine power of the model occurs at a speed of 80 rpm, which is equal to 333.1 watts. However, laboratory data shows maximum turbine power as 290.6 watts at 100 rpm, which is 23.40% lower than the simulation result. According to the results, the two-dimensional simulation approach tends to overestimate the values compared to the actual data. Among the contributing factors to this inaccuracy are using 2D simulation and ignoring the gradient of velocity and pressure in the Z-axis, not considering the turbine’s axis and blade-axis connections in the fluid’s domain, not considering the blades tip vortices and interaction of vortices with blades in the third dimension. Since Supplying the electricity to off-grid areas in form of distributed generation by using renewable resources have been considered to be one of the main components of sustainable development in the field of energy, vertical axis wind turbines proposed in this study are viable alternatives to commonly used diesel generator for areas with appropriate wind potential.


[1].          https://rc.majlis.ir/fa/law: Accessed January 15, 2022
[2] Noorollahi Y, Yousefi H, Mohammadi M. Multi-criteria decision support system for wind farm site selection using GIS. Sustainable Energy Technologies and Assessments. 2016; 13: 38-50.
[3].          Østergaard P.A, Duic N, Noorollahi Y, Mikulcic H, Kalogirou S. Sustainable development using renewable energy technology. Renewable energy. 2020; 146: 2430-2437.
[4]. Adibfar A. wind power plant. 1st ed. Tehran: Pendarpars; 2016 [Persian]
[5]. Amini Sh, Golzarian M. Simulation of 3-blade darrieus vertical axis wind turbine. National biomechanic congress. 2017 [Persian].
[6].          B.C. Cochran, Damiani R.R. Harvesting wind power from tall buildings. CTBUH 8th world congress. 2008.
[7].          Bravo R, Tullis S, Ziada S. Performance testing of a small vertical-axis wind turbine. Proceedings of the 21st Canadian Congress of Applied Mechanics. 2007.
[8].          Danao L.A, Edwards J, Eboibi O, Howell R. A numerical investigation into the influence of unsteady wind on the performance and aerodynamics of a vertical axis wind turbine. Applied Energy. 2014; 116: 111-124.
[9].          Lanzafame R, Mauro S, Messina M. 2D CFD modeling of H-Darrieus wind turbines using a transition turbulence model. Energy Procedia. 2014; 45: 131-140.
[10]. Rezaeiha A, Kalkman I, Blocken B. CFD simulation of a vertical axis wind turbine operating at a moderate tip speed ratio: guidelines for minimum domain size and azimuthal increment. Renewable energy. 2017; 107: 373-385.
[11]. Subramanian A, Sivanandan H, Giri A, Madhavan V, Vivek M, Velamati R. Effect of airfoil and solidity on performance of small scale vertical axis wind turbineusing three dimensional CFD model. Energy. 2017; 133: 79-190.
[12]. Chaisiriroj P, Tinnachote N, Usajantragul S, Leephakpreeda T. Experimental performance investigation of optimal vertical axis wind turbines under actual wind conditions in Thailand. Energy Procedia. 2017; 138: 651-656.
[13]. Elsakka M, Ingham B, Ma L, Pourkashanian M. CFD analysis of the angle of attack for a vertical axis wind turbine blade. Energy Conversion and Management. 2019; 182: 54-165.
[14]. Afif A, Wulandari P, Syahriar A. CFD analysis of vertical axis wind turbine using Ansys fluent. Journal of Physics: Conference Series 1517. 2020.
[15]. Noorollahi Y, Ghanbari S, Tahani M. Numerical analysis of a small ducted wind turbine for performance improvement. International Journal of Sustainable Energy. 2019; 39: 290-307.
[16]. Rogowski K, Hansen M.O.L, Bangga G. Performance Analysis of a H-Darrieus Wind Turbine for a Series of 4-Digit NACA Airfoils. Energies. 2020; 13(12): 3196.
[17]. McLaren K, Tullis S, Ziada S. Computational fluid dynamics simulation of the aerodynamics of a high solidity, small‐scale vertical axis wind turbine. Wind Energy. 2012; 15(3): 349-361.