Abstract:
Water is the most important source of life, and it is presently accessed through pumps. Centrifugal
and positive displacement pumps are two types of pumps, with electrical, diesel, and renewable
energy sources (Solar and Wind energies) as inputs. To solve environmental issues, wind energy
has emerged as a new energy option. Wind energy is converted to the required energy using
turbines. Based on the rotation axis, they are divided into two categories: horizontal and vertical.
The Savonius wind rotor is a vertical axis wind turbine (VAWT) with a simple structure and a low
operating speed, making it ideal for places with low average wind speeds. However, its application
areas are limited due to its low performance. According to studies, the shape and number of
blades, rotor stage, shaft influence, overlap ratio, endplate, blade angle of twist, aspect ratio, and
fin addition all have a significant impact on S-VAWT performance.
The purpose of this study is to use CFD methods to improve the performance of the S-VAWT for
the water pumping system in the Dodota area by modifying aspect ratios and adding fins to the
blade, and to compare the results to previous literature. The power delivered by the rotor is around
12.8 W while the power available in the wind is 40 W. From the wind power, the size of the rotor
is calculated to pump the water needed. The rotor contains four turbine blades with a rotor
diameter of 3 m, an endplate diameter of 3.3 m, a rotor height of 2.4 m, and an aspect ratio of 0.8.
SOLIDWORK 2018 was used to create the 3D model of the Savonius rotor, and ANSYS 19.2 was
utilized to simulate it. The study was carried out throughout the dry season using the National
Metrology Agency of Ethiopia wind speed data, with an average value of 2.15 m/s. The fin is used
to direct the wind flow by filling the space in the blades. The results showed that when two fins are
added, the pressure distributions and velocity distributions are higher than when only one fin is
used or when without a fin is used. With the addition of two blades, the power coefficient, 𝐶𝑝 in
this study increases by an average of 0.256. This result is higher compared to previously done by
Ridwan et al, 2019 which was 0.241.
