The interactions of I-65° type cylinder and Savonius wind turbine for performance improvement

Abstract

Several advantages of the Savonius wind turbine, among others independent of wind direction, simple and cheaper in its design and higher starting torque at low wind streams. However, The Savonius wind turbine has the lowest peak coefficient of power compared to another type of wind turbines. This fact act as the reason much research conducted to augment the performance of turbine Savonius. This study experimentally investigated the capabilities of the Savonius wind turbine by mounting an I-65° type cylinder upstream of the convex returning blade. Based on the free stream velocity maintained at U = 9 m/s and the characteristic length of L = 2D-e (where D is blade diameter, and e is thick of blade), the Reynolds number (Re) can be then calculated to produce Re = 1.78 × 105, and implemented for carry out this experimental study. The space between the cylinder I-65° type to the center of the convex turbine blade fixed for 1.2≤S/D≤2.2. The diameter of I-65° type cylinder determined fixed at 0.5 times diameter turbine blade. The experiment result shows that the mounting of the cylinder I-65° type upstream of the convex turbine blade is useful for improving turbine performance. This improvement has clearly proven optimized for the Reynolds Number Re = 1.78 × 105. The coefficient power (Cp) of the turbine with the cylinder I-65otype is higher than the conventional Savonius wind turbine. The maximum power coefficient (Cp) of the Savonius turbine equipped with I-65° type cylinder increases up to 19.64% compared to the conventional turbine. These excellent results obtained for Tip Speed Ratio (λ) of 0.58.