Numerical Study of the Effect of Deflector Angle on the Performance of Twin Savonius Hydrokinetic Turbines in a Side-by-Side Configuration in The Cooling Water Channel of The Paiton Power Plant, Indonesia

Water energy is a type of renewable energy with enormous potential in Indonesia. This study presents the effect of deflector angles on the performance of two side-by-side Savonius hydrokinetic turbines installed in the cooling water channel of the Paiton Power Plant. The study employs numerical simulation using Ansys Fluent 2023 R2 software. Simulations were conducted with the configuration of two side-by-side turbines rotating in the opposite direction. The research explores variations in deflector angles, specifically nine different angles denoted as α and β. The turbines used are two-blade Savonius turbines with blade diameter (D) of 578 mm, shaft diameter (b) of 40 mm, turbine diameter (L) of 1100 mm, blade thickness (t) of 8 mm, and turbine height (H) of 1100 mm. This study's results indicate that installing a deflector on the upstream side effectively increases the coefficient of power and the self-starting capability of the Savonius hydrokinetic turbine across all deflector angle variations. The maximum coefficient of power of the Savonius hydrokinetic turbine, 0.36033, was achieved at a deflector angle of β = 51.8° and α = 48.05° with an optimal tip speed ratio of 1,2.