Volume 9 Issue 3 ( September 2022 )

Pages_645-653

Performance Analysis of a Modified Savonius Rotor Using a Variable Blade Thickness

Mohanad Al-Ghriybah

[ABSTRACT ]

Wind power is one of the green energies that could be used for meeting these energy demands. This is attributed to the fact that such a source of power is free and widely available. Savonius wind rotor can work at low wind speeds which fits well the rural areas. Despite its cheap, robust, and simple design, the Savonius rotor has some negatives such as relatively low efficiency and high fluctuations of static torque. Given this, the main goal of this research is to improve the output power of the Savonius wind rotor by varying the blade thickness using numerical simulation. Investigation methods based on the rotational speed of the rotor tip, wind field characterizations, torque, and power coefficients are conducted. The K-Ɛ/realizable model was utilized for simulating the rotor at 9 m/s wind speed via Ansys Fluent software. Results demonstrate that the newly-developed rotor with varying blade thickness has a less wind wake on the internal surface of the returning blade. Moreover, the suction vortices have a higher velocity for the new configuration causing a reduction in pressure on the outer side of the returning rotor which indicates less negative torque. Compared with the traditional Savonius blades, the new model shows a 40% performance enhancement in the maximum power coefficient. The maximum power coefficient is found to be 0.20. This configuration can be useful for small- scale electricity generation in urban areas.

Keywords: Savonius; Wind power; VAWT; Wind turbine

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