الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The interest in the wind energy is increasing dramatically nowadays. Many researchers are interested to improve the turbine output power in order to meet the global energy demand. The present study investigates the aerodynamic characterizes of Savonius rotor, by innovating a novel blade which has a higher power coefficient.The aim of the present study is to study some of the factors that may increase the power of Savonius rotor. This was done by analyzing the effect of twisting blade angles of three-dimensional rotor and find the optimal angle of twisting. Numerical simulation has been performed using sliding mesh technique of ANSYS software. The four turbulence models; realizable 𝑘−𝜀, standard 𝑘−𝜀, 𝑆𝑆𝑇 transition and 𝑆𝑆𝑇 𝑘−𝜔 are selected to find out which one is suitable for the present case. The realizable 𝑘−𝜀 turbulence model shows more accurate results compared to others. For two-dimensional simulation four ways of rotor blade modifications have been studied: combined elliptical, adjoint and random modification methods. The simulation results compared with that obtained from the classical blades. For three-dimensional simulation the method of random modification was selected. Moreover, the influence of shaft diameter, overlap ratio and blades number were conducted. The chosen twisting angles are; 12.5°,25° and 35° and applied at classical blades and two choices of novel blades. The power coefficient of the rotor reaches a maximum value at tip speed ratio (𝝀) of 0.7 and is equal to 0.237 of two-dimensional rotor for optimum design. The optimum design for the three-dimensional rotor the power coefficient reaches a maximum value equal to 0.206 at (𝝀) of 0.7. The present study shows the increasing of power coefficient by the twisting blades, where the optimal twisting angles of two optimum design is 35°.