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.