Flow-induced vibration of a circular cylinder at limiting structural parameters

Transverse oscillation of a dynamically supported circular cylinder in a flow at Re = 100 has been numerically simulated using a high-resolution viscous-vortex method, for a range of dynamical parameters. At the limiting case with zero values of mass, damping and elastic force, the cylinder oscillates sinusoidally at amplitude A/D = 0.47 and frequency fD/U-infinity = 0.156. For zero damping, the effects of mass and elasticity are combined into a new, "effective" dynamic parameter, which is different from the classic "reduced velocity". Over a range of this parameter, the response exhibits oscillations at amplitudes up to 0.6 and frequencies between 0.15 and 0.2. From this response function, the classic response in terms of reduced velocity can be obtained for fixed values of the cylinder/fluid ratio m*. It displays "lock-in" at very high values of m*. (C) 2001 Academic Press.