Effect of water level variation in canal on energy Harvesting capacity of the Savonius turbine

Most studies on Savonius turbines have been conducted under constant water level conditions, assuming complete submergence of the rotor. However, in a real-world canal, the water level varies significantly throughout the year, which can influence turbine performance. To address this gap, this experimental investigation is conducted for the submerge ratio (SR) ranges from 0.076 to −0.199. The effect of water level variation is generated by lifting the turbine from the 67 mm depth of the water (0.076 SR) to the −17.5 cm height from the free surface of the water (−0.199 SR), while the flow depth of 88 cm and flow velocity of 0.37 m/s maintain constant throughout the study. According to the ANOVA study, SR has a significant impact on performance , and the rotor kept at 100 % submersion with an SR of 0.076 yields the optimal C p of 0.1925. Additionally, the maximum Cp remains almost constant for all positive SR, but it profoundly affects Cp at higher TSR. The findings clearly indicate that the positive SR should be maintained above 0.028 to ensure a uniform velocity and to eliminate the effect of water level fluctuations across the rotor. The Cp of the rotor decreases with a rise in the negative SR, and for the −0.199 SR, the rotor stops rotating even under no load conditions.