ANALISIS ALIRAN FLUIDA PENGARUH PENAMBAHAN SILINDER SIRKULAR PADA SISI ADVANCING BLADE TERHADAP PERFORMA TURBIN AIR SAVONIUS MENGGUNAKAN MYRING BLADE N=1 Dan N=2.
Vertical savonius turbine is a water turbine that can rotate at low flow rate with high initial torque so that it is suitable to use in indonesian waters. in the previous research, experiments on savonius turbines were done by modifying blade shape with myring equation so that its performance can be improved but the increase is not optimal yet. This research would analyze the performance of savonius water turbines with Myring blade equation n=1 & n=2 and add a circular cylinder next to the advancing blade which used computational fluid dynamic (CFD) method. 2D design of gambit-fluent software was used in preprocessing stage. The turbine is simulated in open water channel condition with 8400 mm x 1100 mm dimension and current speed of 0.22m/s. The cylinder diameter variations used are ds/D= 0.2; 0.3 and 0.4. Ansys-fluent software was used in the solution and post processing stages. Turbulent models used k-epsilon. Its spartial discretization used was second order. The results were the value of torque and power coefficient, velocity and pressure contour and pressure distribution. It shows that savonius water turbines with myring variation n=1 with cylinder diameter ds/D=0.4 reach the highest power coefficient of 0.5146 and an increase of 40,0659% compared with myring n=1 without any cylinder. Myring variation n=2 with cylinder diameter ds/D=0.4 reach the second highest power coefficient of 0.5028 and an increase of 53.3079% compared with myring n=2 without any cylinder.