Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2015.783.791ZahariM.A.DolS.S.52015155Vortex-Induced Vibration (VIV) is the turbulent motion induced on bluff body that creates irregular lift forces and results in alternating movement of the body. Vortex-Induced Vibration (VIV) powered system seems a viable idea of alternative source of energy as it has the ability to take advantages of low current speed of water. This work aims to investigate the effects of different sizes of cylinder diameter on VIV system. The study is vital in order to maximize and exploit VIV efficiently to transform the turbulent kinetic energy into valuable source of energy. Five cylinders with the range of 0.25-2.00 inches diameter are tested at water velocity of 0.453 m sec‾^{1} to study the behavior of VIV by using a water tunnel facility specifically developed for this study. Results from this experiment indicates that, the 2.0 inches cylinder gives the highest amplitude of oscillation motion that is equal to 0.0065 m within the range of Reynolds number (300<Re<300000). In term of power generated, the 2.0 inches cylinder produces the maximum result of 0.0141 W.]]>Ball, I., T. Killen, S. Sakhuja and E. Warner,2012Bernitsas, M.M., K. Raghavan, Y. Ben-Simon and E.M. Garcia,2006Blevins, R.D.,1974Cengel, Y.A. and J.M. Cimbala,2006Goffman, E.,2008Hall-Stinson, A., C. Lehrman and E. Tripp,2011Hennessey, T.V.,2005Lee, J.H. and M.M. Bernitsas,2011Mehta, R.D.,1985Yaakob, O., T.M.A.T. Ab Rashid and M.A.A. Mukti,2006Park, H., R.A. Kumar and M.M. Bernitsas,20134 Re1.2x10^{5}.]]>Roshko, A.,1952Sharma, R.C. and N. Sharma,2013Techet, A.,2005Williamson, C.H.K. and R. Govardhan,2004Zahari, M.A.,2014Zahari, M.A. and S.S. Dol,2014