Aerodynamic Performance Investigations of Savonius Twin-rotor Wind Turbines

Document Type : Regular Article


1 Center for Renewable Energies Development, CDER, BP 62 Road of the Observatory, Bouzareah, 16340, Algiers, Algeria

2 Mohamed Bougara University, Technology Faculty, Mechanical Engineering Department, Boumerdes, Algeria



The aim of this study is to evaluate the aerodynamic efficiency of a Savonius vertical-axis wind turbine. The approach used relies on resolving the Unsteady Reynolds Averaged Navier-Stokes equations (URANS), the turbulence being modeled by the k-ω SST model. The flow around the wind turbine is simulated using the arbitrary sliding interfaces technique. First, the study investigates the impact of blade shape on wind turbine efficiency by examining seven Savonius rotors constructed with distinct blade configurations. The results indicate that the highest aerodynamic performance is provided by the rotor with the elliptical blades, with a notable increase in the power coefficient of about 80% in comparison to the classic semi-circular profile. To further enhance the efficiency of the Savonius wind turbine, a twin-rotor configuration using the elliptical blades was studied. The results indicate a further enhancement in the power coefficient, reaching 110% compared to a single rotor with semicircular blades.


Main Subjects

Akwa, J. U., Vielmo, H. A., & Petry, A. P. (2012). A review on the performance of Savonius wind turbines. Renewable Sustainable Energy Review, 16(5), 3054–3064.
Al-kayiem, H. H., Bhayo, B. A., & Assadi, M. (2016). Comparative critique on the design parameters and their effect on the performance of S-rotors. Renewable Energy, 99, 1306–1317.
Alom, N., & Saha, U. K. (2019a). Evolution and progress in the development of savonius wind turbine rotor blade profiles and shapes. Journal of Solar Energy Engineering, 141(3), 030801.
Alom, N., & Saha, U. K. (2019b). Influence of blade profiles on Savonius rotor performance: Numerical simulation and experimental validation. Energy Conversion and Management, 186, 267–277.
Alom, N., Kolaparthi, S. C., Gadde, S. C., & Saha, U. K. (2016). Aerodynamic design optimization of elliptical-bladed Savonius-stype wind turbine by numerical simulations. International Conference on Offshore Mechanics and Arctic Engineering. American Society of Mechanical Engineers.
Altan B. D., & Gungor, A. (2022). Examination of the effect of triangular plate on the performance of reverse rotating dual Savonius wind turbines. Processes, 10.22378. https:// / 10.3390/pr10112278.
Ashwindran, S. N., Azizudin, A. A., & Oumer, A. N. (2020). A moment coefficient computational study of parametric drag driven wind turbine at moderate tip speed ratios. Australian Journal of Mechanical Engineering. 20(2), 433-447.
Bach, G. (1931). Untersuchungen uber savonius rotoren und verwandte stromungsmaschinen. Forschung Auf Dem Gebiet Des Ingenieurwesens A, 2(6), 218–231.
Banerjee, A., Roy, S., Mukherjee, P., & Saha, U. K. (2014). Unsteady flow analysis around an elliptic bladed Savonius style wind turbine Gas Turbine India Conference. American Society of Mechanical Engineers.
Bekhti, A., Maizi, M., Guerri, O., Laazab, S., Bouzidi, S. C., & Boumerdassi, K. (2018, November). Numerical analysis of dynamic stall on wind turbine airfoils International Conference on Wind Energy and Applications in Algeria. IEEE.
Bekhti, A., Maizi, M., Tata, M., & Laazab, S. (2019, November). Numerical Investigation of Turbulent Flow over a Vertical axis Wind Turbine 7th International Renewable and Sustainable Energy Conference. IEEE.
Benesh, A. H. (1988). Wind turbine system using a vertical axis Savonius type rotor. U.S. Patent No: US5494407A.
Bhayo, B. A., & Al-kayiem, H. H. (2017). Experimental characterization and comparison of performance parameters of S-rotors for standalone wind power system. Energy, 138, 752–763.
Chan, C. M., Bai, H. L., He, D. Q. (2018). Blade shape optimization of the Savonius wind turbine using a generic algorithm. Applied Energy, 213, 148–157.
Chen, L., Chen, J., & Zhang, Z. (2018). Review of the savonius rotor's blade profile and its performance. Journal of Renewable and Sustainable Energy, 10, 013306.
Dewan, A., Gautam, A., & Goyal, R. (2021). Savonius wind turbines: A review of recent advances in design and performance enhancements. Materials Today: Proceedings, 47, 2976-2983. https://doi. org / 10.1016 / j.marpr.2021.05.205
Diaz, A. P., Parajo, G. J., & Salas, K. U. (2015). Computational model of Savonius turbine. INgeniare. Revista chilena de Ingenieria, 23(3), 406–412.
Dobrev, I., & Massouh, F. (2011). CFD and PIV investigation of unsteady flow through Savonius wind turbine. Energy Procedia, 6, 711–720.
Driss, Z., Mlayeh, O., Driss, D., Maaloul, M., & Abid, M. S. (2014). Numerical simulation and experimental validation of the turbulent flow around a small incurved savonius wind rotor. Energy, 74, 506–517.
Duan, Z., Jia, F., & Wang, Z. J. (2020). Sliding mesh and arbitrary periodic interface approaches for the high order FR/CPR method. AIAA Scitech 2020 Forum. Orlando, FL.
Dürrwächter, J., Kurz, M., Kopper, P., Kempf, D., Munz, C. D., & Beck, A. (2021). An efficient sliding mesh interface method for high-order discontinuous Galerkin schemes. Computers & Fluids, 217, 104825,
Ebrahimpour, M., Shafaghat, R., Alamian, R., & Shadloo, M. S. (2019). Numerical inverstigation of the Savonius vertical axis wind turbine and evaluation of the effect of the overlap parameter in both horizontal and vertical directions on its performance. Symmetry, 11(6), 821.
Eecen, P. J., & Verhoef, J. P. (2007). EWTW Meteorological Database Description. ECN-E—07-041, ECN Windenergy, Netherlands
El-Askary, W. A., Saad, A. S., AbdelSalam, A. M., & Sakr, I. M. (2018). Investigating the performance of a twisted modified Savonius rotor. Journal of Wind Engineering & Industrial Aerodynamics, 182, 344–355.
El-Baz, A. R., Youssef, K., & Mohamed, M. H., (2016). Innovative improvement of a drag wind turbine performance. Renewable Energy, 86, 89–98.
Etemadeasl, V., Esmaelnajad, R., Farzaneh, B. & Jafari, M. (2021). Application of counter rotating rotors for improving performance of savonius turbines. Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, 45, 473485.
Fujisawa, N. (1992). On the torque mechanism of Savonius rotors. Journal of Wind Engineering and Industrial Aerodynamics, 40, 277-292.
Guerri, O., Hamdouni A., & Sakout, A. (2008). Numerical simulation of the flow around oscillating wind turbine airfoils. Part 1: Forced oscillating airfoil. International Journal of Multiphysics, 2(4).
Guerri, O., Sakout A., & Bouhadef, K. (2007) Simulation of the fluid flow around a rotating vertical axis wind turbine, Wind Engineering, 31(3).
Hesami, A., Nikseresht, A. H., & Mohamed, M. H. (2022). Feasibility study of twin-rotor Savonius wind turbine incorporated with a wind-lens. Ocean Enginnering, 247, 110654.
Im, H., & Kim, B. (2022). Power performance analysis based on Savonius wind turbine blade design and layout optimization through rotor wake flow analysis. Energies, 15, 9500. / 10.3390 / en15249500
Johannes, S. S. (1929). Rotor adapted to be driven by wind or flowing water. U. S. p. N. 1697574.
Kacprzak, K., Liskeiwicz, G., & Sobczakb, K. (2013). Numerical investigation of conventional and modified Savonius wind turbines. Renewable Energy, 60, 578–585.
Kamoji, M. A., Kedare, S. B., & Prabhu, S. V. (2008). Experimental investigations on the effect of overlap ratio and blade edge conditions on the performance of conventional savonius rotor. Wind Engineering, 32 (2), 163–178.
Menter, F. R. (1993). Zonal Two equation k-ω turbulence models for aerodynamic flows. AIAA Paper, 93-2906.
Meziane, M., Essadiqi, E., Faqir, M., & Ghanameh, M. F. (2019). CFD study of unsteady flow through Savonius wind turbine clusters. International Journal of Renewable Energy Research, 9(2), 657666.
Mohamed, M. H., Janiga, G., Pap, E., & Thévenin, D. (2011). Optimal blade shape of a modified Savonius turbine using an obstacle shielding the returning blade. Energy Conversion and Management, 52(1), 236–242.
Patel, U. K., Alom, N., & Saha, U. K. (2023). Aerodynamic analysis of a 2-stage elliptical-bladed Savonius wind rotor: Numerical simulation and experimental validation. International Journal of Green Energy. / 15435075.2023 – 2194975
Rahai, H. R. (2005). Development of optimum design configuration and performance for vertical axis wind turbine. Feasibility Analysis and Final EISG Report; California Energy Commission: Sacramento, CA, USA.
Roy, S., & Saha, U. K. (2013). Review on the numerical investigation into the design and development of Savonius wind rotors. Renewable Sustainable Energy Review, 2, 73–83.
Saha, U. K., Thotla, S., & Maity, D. (2008). Optimum design configuration of Savonius rotor through wind tunnel experiments. Journal of Wind Engineering and Industrial Aerodynamics, 96(8), 1359–1375.
Sevasegaram, S. (1978). An experimental investigation of a class of resistance-type direction independent wind turbines. Energy, 3(1), 23–30.
Shaheen, M., El-Sayed, M., & Abdallah, S. (2015). Numerical study of two bucket Savonius wind turbine cluster. Journal of Wind Engineering and Industrial Aerodynamics, 137, 78–89.
Shashikumar, C. M., Honnasiddaiah, R., Hindasageri, V., & Madav, V. (2021). Experimental and numerical investigation of novel V-shaped rotor for hydropower utilisations. Ocean Engineering, 224, 108689.
Sun, X., Luo, D., Huang, D., & Wu, G. (2021). Numerical study on coupling effects amoung multiple Savonius turbines. Journal of Renewable and Sustainable Energy, 4, 053107.
Tata, M., Smaili, A., & Masson, C. (2018). Effect of grid topology on numerical simulations of flow fields around wind turbine nacelle anemometer. Journal of Applied Fluid Mechanics, 11(6), 1569–1578.
Zhou, T., & Rempfer, D. (2013). Numerical study of detailed flow field and performance of Savonius wind turbines. Renewable Energy, 51, 373–381.