Savonius wind turbine is an interesting type of vertical axis wind turbines (VAWTs) which has a low cost of manufacturing, however, this turbine has a relatively low power output compared to the other types of VAWTs. Further study is required to enhance its performance to match the high demand of the power generation in small-scale applications. The main objective of the current study is to enhance the power output coefficient (Cp) of the conventional Savonius rotor by adding two-inner blades to the geometry. The performance assessment was performed for five different angles of inner blades (100°, 120°, 140°, 160°, and 180°). Moreover, the effect of spacing between inner blades was numerically examined for three values of spacing i.e. 0.02, 0.01, and 0.005 m. The current two-dimensional simulation was performed utilizing the Ansys Fluent solver. The simulation results affirmed that the maximum enhancement to be 32.9% compared to the conventional rotor at TSR equal to 0.7 when the spacing between inner blades is 0.005 m with an inner blades angle of 100°. Moreover, results demonstrated that the Ct max is 0.435 at TSR = 0.4 for the rotor with 160° inner blades and a spacing of 0.005 m.

Savonius风力涡轮机是一种有趣的垂直轴风力涡轮机（VAWT），其制造成本较低，但是，与其他类型的VAWT相比，该涡轮机的功率输出相对较低。需要进一步研究以增强其性能，以适应小规模应用中对发电的高要求。当前研究的主要目的是通过在几何结构上增加两个内叶片来提高常规Savonius转子的功率输出系数（Cp）。对内刀片的五个不同角度（100°，120°，140°，160°和180°）进行了性能评估。此外，对于三个间距值（即0.02、0.01和0.005 m），通过数值检查了内叶片之间的间距的影响。当前的二维仿真是使用Ansys Fluent求解器进行的。仿真结果证实，当内叶片之间的间距为0.005 m，内叶片角度为100°时，在TSR时，与常规转子相比，最大增强为32.9％，等于0.7。此外，结果表明，对于带有160°内叶片且间距为0.005 m的转子，在TSR = 0.4时Ct max为0.435。