Bahmani - Graduate student, Dept. of Mech. Eng. Shiraz University, Shiraz, Iran
Akbari - Assistant Professor, Dept. of Mech. Eng. Shiraz University, Shiraz, Iran

In this paper we present numerical results of the dynamic response to fluid forcing on an elastically mounted rigid cylinder with low mass-damping, allowed to oscillate transverse to a free stream. A vortex method is implemented to solve the two-dimensional Navier-Stokes equation in terms of vorticity. The Reynolds number ranges from 90 to 160, a regime that is fully laminar. The main objective of this paper is to investigate the effect of damping ratio on the transverse vibrational behavior of the cylinder. Numerical results predict that a decrease in damping ratio will result in an increase in the oscillation amplitude, while it will cause an increase in the velocity range over which lock-in occurs. The changes are not linear with respect to variation in damping ratio.

Vortex-induced vibration; Damping-ratio; Circular cylinder; Vortex method