CFD study of Savonius wind turbine: 3D model validation and parametric analysis

A CFD study is conducted in order to characterize the dynamic behavior of a Savonius vertical axis wind turbine. All simulations are executed using the open source code, OpenFOAM. Both two-dimensional and full three-dimensional cases have been investigated in order to provide a suitable tool for geometrical optimization of this rotor. Unsteady simulations are carried out at different tip speed ratio (TSR), varying angular speed of rotor at constant wind speed, using different one and two-equation URANS turbulence models and selecting the k−ω SST for the final analysis. The two-dimensional model was compared with experimental data available in literature and obtained from tests in wind tunnel. This simplified model shows an over-estimation of experimental data, reporting a maximum efficiency at TSR 1, 20% higher than experimental value. The results of 3D model are in good agreement with experiments with a peak of 0.202 at TSR 0.8 for a rotor with aspect ratio 1.1. The influence of the rotor height has been evaluated on flow dynamics of the turbine and its power coefficient.

[1]  M. A. Kamoji,et al.  Experimental investigations on single stage modified Savonius rotor , 2009 .

[2]  R. Ricci,et al.  Unsteady Aerodynamics of a Savonius wind rotor: a new computational approach for the simulation of energy performance , 2010 .

[3]  Yuan Zheng,et al.  Research on the improvement of the performance of savonius rotor based on numerical study , 2009, 2009 International Conference on Sustainable Power Generation and Supply.

[4]  Grzegorz Liskiewicz,et al.  Numerical investigation of conventional and modified Savonius wind turbines , 2013 .

[5]  Ivan Dobrev,et al.  CFD and PIV investigation of unsteady flow through Savonius wind turbine , 2011 .

[6]  D. Wilcox.  Turbulence modeling for CFD , 1993 .

[7]  S. Sivasegaram.  Secondary parameters affecting the performance of resistance-type vertical-axis wind rotors , 1978 .

[8]  João Vicente Akwa,et al.  Discussion on the verification of the overlap ratio influence on performance coefficients of a Savonius wind rotor using computational fluid dynamics , 2012 .

[9]  A. A. El-Haroun,et al.  AN EXPERIMENTAL STUDY ON IMPROVEMENT OF SAVONIUS ROTOR PERFORMANCE , 2012 .

[10]  M. A. Kamoji,et al.  Performance tests on helical Savonius rotors , 2009 .

[11]  F. Menter.  Improved two-equation k-omega turbulence models for aerodynamic flows , 1992 .

[12]  I. Ross.  Wind Tunnel Blockage Corrections: An Application to Vertical-Axis Wind Turbines , 2010 .

[13]  T. Shih,et al.  A new k-ϵ eddy viscosity model for high reynolds number turbulent flows , 1995 .

[14]  Seach Chyr Goh,et al.  Numerical simulation of a Savonius turbine above an infinite-width forward facing step , 2016 .

[15]  Zied Driss,et al.  Experimental investigation of helical Savonius rotor with a twist of 180 , 2013 .

[16]  Zbigniew Bulinski,et al.  Numerical modeling and preliminary validation of drag-based vertical axis wind turbine , 2015 .

[17]  Emanuela Colombo,et al.  A methodology for qualifying industrial CFD: The Q3 approach and the role of a protocol , 2012 .

[18]  M. H. Nasef,et al.  Evaluation of Savonius rotor performance: Static and dynamic studies , 2013 .

[19]  P. Moin,et al.  Eddies, streams, and convergence zones in turbulent flows , 1988 .

[20]  S. Sivasegaram.  Design parameters affecting the performance of resistance-type, vertical-axis windrotors - An experimental investigation , 1977 .

[21]  P. Spalart.  A One-Equation Turbulence Model for Aerodynamic Flows , 1992 .

[22]  Haixia Liu,et al.  Review of fluid dynamics aspects of Savonius-rotor-based vertical-axis wind rotors , 2014 .

[23]  B. F. Blackwell,et al.  Wind tunnel performance data for two- and three-bucket Savonius rotors , 1978 .

[24]  Yasushi Takeda,et al.  Interactive flow field around two Savonius turbines , 2011 .

[25]  Baowei Song,et al.  Computational Fluid Dynamics Prediction of a Modified Savonius Wind Turbine with Novel Blade Shapes , 2015 .

[26]  François Garde,et al.  An analysis of the transient forces acting on Savonius rotors with different aspect ratios , 2013 .