Performance analysis of a Savonius hydrokinetic turbine with aerodynamic blade shape and different overlap ratios: A numerical flow-driven approach.

This study focuses on improving the performance of Savonius hydrokinetic turbines (SHTs) by analyzing the influence of blade aerodynamics and varying overlap ratios ( e D = 0 to 0.15). The study compares the performance of conventional and a new type of Savonius turbine blade, referred to as S R 5050. The study uses the incompressible SST k − ω model to evaluate the performance of a rotor under an upstream velocity of 0. 46 m s , with the numerical flow-driven approach where no artificial rotor motion has been provided. The results show that the new blade shape of the S R 5050 rotor outperforms conventional rotors in all e D ratios. The blade shape of the S R 5050 rotor effectively captures the energy of fluid passing between the blades, increasing both the coefficient of power C p and the coefficient of torque C m . The S R 5050 rotor with an e D ratio of 0.15 displays the highest value of C p at 0.38. It shows a maximum performance improvement of 39.19% over conventional rotors. For conventional rotors, the highest values of C m were observed at rotor position around ≈ 15 ° and ≈ 195 ° , while for S R 5050 rotors with all e D ratios, the highest values of C m were observed at rotor position of ≈ 20 ° and ≈ 200 °. [Display omitted] • Influence of aerodynamic blade shape (SR5050) on the SHT. • Influence of different overlap ratios on the SHT. • Increasing the overlap ratio results in higher mean value of the TSR, C m and C p. • The S R 5050 shows better starting characteristics. • The S R 5050 exhibited a 39.19% increase in C p = 0. 38 compared to the conventional rotor. [ABSTRACT FROM AUTHOR]