# KAJIAN NUMERIK PENGARUH VARIASI SUDUT STAGGER DAN DIAMETER SILINDER SIRKULAR DI SISI ADVANCING BLADE TERHADAP KINERJA TURBIN AIR SAVONIUS BERSUDU KOMBINASI MYRING N=1 DAN N=2

### Abstract

Indonesia has a great potential to use water currents as an energy source that can be converted into electricity. Savonius water turbines can be used as its solution to make it. Its performance can be improved by modifying its combined blades with myring n=1 and n=2 and also by adding a circular cylinder on it. The Computational Fluid Dynamics (CFD) method with Ansys 17.2-Fluent and Tecplot software are chosen and used for its flow characteristics study produced by the turbine. Gambit software is also used to create geometry and domain models. The boundary condition of the model include the inlet as the input properties area with an initial velocity of 0.22 m/s as analysis limitation of control surface on the test model. The modification include the use of combined blade with myring n=1 and n=2. One circular cylinder is added in front of the advancing blade so that the flow velocity will be higher and its efficiency can be increased. Circular cylindrical diameters are various i.e. ds/D=0.2; 0.3 and 0.4 with 0˚, 30˚ and 60˚ stagger elevation angles. The results obtained from this research are the values of torque coefficient (Cm), power coefficient (Cp), pressure distribution and fluid flow characteristics. Turbine performance has the highest increase (35.86%) on ds/D =0.4 with 60˚ stagger elevation angle variation. The greatest decrease (30.11%) occured on ds/D=0.4 0˚ stagger elevation angle variation without using circular cylinder.