Wind tunnel testing and numerical simulation on aerodynamic performance of a three-bladed Savonius wind turbine

The purpose of this research work is to investigate experimentally and computationally the feasibility of improving the performance of the vertical-axis Savonius wind turbine. The authors first performed a series of wind tunnel investigations on semi-cylindrical three-bladed Savonius rotor scale models with different overlap ratios and without overlap. These experiments were conducted in front of a low-speed subsonic wind tunnel at different Reynolds numbers. Pressures around the concave and convex surfaces of each blade, as well as the static torque for the rotor models, were measured. Using these experimental data, the authors calculated aerodynamic characteristics such as drag coefficients, static torque coefficients, and power coefficients. The authors then performed computational fluid dynamics (CFD) simulations using the commercial CFD software FLUENT and GAMBIT to analyze the static rotor aerodynamics of those models. The experimental and computational results were then compared for verification. Three different models with different overlap ratios were designed and fabricated for the current study to find the effect of overlap ratios. The results from the experimental part of the research show a significant effect of overlap ratio and Reynolds number on the improvement of aerodynamic performance of the Savonius wind turbine. At higher Reynolds number, the turbine model without overlap ratio gives better aerodynamic coefficients, and at lower Reynolds number, the model with moderate overlap ratio gives better results.

[1]  Jyeshtharaj B. Joshi,et al.  Optimisation of vertical axis wind turbine: CFD simulations and experimental measurements , 2012 .

[2]  Rajat Gupta,et al.  COMPARATIVE STUDY OF A THREE-BUCKET SAVONIUS ROTOR WITH A COMBINED THREE-BUCKET SAVONIUS–THREE-BLADED DARRIEUS ROTOR , 2008 .

[3]  Brian H. Dennis,et al.  Aerodynamic Shape Optimization of a Vertical-Axis Wind Turbine Using Differential Evolution , 2012 .

[4]  Tsutomu HAYASHI,et al.  Wind Tunnel Tests on a Three-stage Out-phase Savonius Rotor , 2004 .

[5]  B. Launder,et al.  Lectures in mathematical models of turbulence , 1972 .

[6]  Khandakar Niaz Morshed,et al.  Experimental and Numerical Investigations on Aerodynamic Characteristics of Savonius Wind Turbine with Various Overlap Ratios , 2010 .

[7]  Ryspek Usubamatov,et al.  Investagation and Design Impeller Type Vertical Axis Wind Turbine , 2011 .

[8]  Nobuyuki Fujisawa,et al.  Experimental Study on the Aerodynamic Performance of a Savonius Rotor , 1994 .

[9]  Mosfequr Rahman,et al.  Experimental and Numerical Investigations on Drag and Torque Characteristics of Three-Bladed Savonius Wind Turbine , 2009 .

[10]  Yan Li,et al.  Wind Tunnel Tests on a Different Phase Three-Stage Savonius Rotor , 2005 .

[11]  Jan Kumbernuss,et al.  INVESTIGATION INTO THE RELATIONSHIP OF THE OVERLAP RATIO AND SHIFT ANGLE OF DOUBLE STAGE THREE BLADED VERTICAL AXIS WIND TURBINE (VAWT) , 2012 .

[12]  Damodar Maity,et al.  Optimum design configuration of Savonius rotor through wind tunnel experiments , 2008 .

[13]  M. A. Kamoji,et al.  WIND TUNNEL TESTS ON A SINGLE STAGE HELICAL SAVONIUS ROTOR , 2007 .

[14]  J. Sargolzaei,et al.  Modeling and simulation of wind turbine Savonius rotors using artificial neural networks for estimation of the power ratio and torque , 2009, Simul. Model. Pract. Theory.

[15]  Robert M Pinkerton Calculated and measured pressure distributions over the midspan section of the NACA 4412 airfoil , 1936 .

[16]  Aydoğan Özdamar,et al.  An experimental study on improvement of a Savonius rotor performance with curtaining , 2008 .

[17]  Nihon-Kikai-Gakkai JSME international journal , 1992 .

[18]  Mosfequr Rahman Torque and drag characteristics of a three bladed savonius rotor , 1999 .

[19]  日本機械学会 Bulletin of JSME , 1958 .

[20]  Tadashi Sawada,et al.  Blade force measurement and flow visualization of Savonius rotors. , 1985 .

[21]  Burçin Deda Altan,et al.  An experimental and numerical study on the improvement of the performance of Savonius wind rotor , 2008 .