Passive control of viv with drag reduction

An experimental investigation has been carried out to measure the drag and vortex-induced vibration amplitudes of a circular cylinder, a circular cross-sectional body with a sinuous axis and a circular cylinder with hemispherical bumps attached. A wide range of Reynolds number has been studied, up to a maximum value of 10(5). Suppression of vortex shedding and drag reductions up to 47% have been observed for the body with a sinuous axis. Drag reductions of about 25% and suppression of vortex shedding have been recorded for the cylinder with bumps. VIV experiments over a range of the mass damping parameter from 2 x 10(-2) to 5 have shown. that amplitudes of oscillation for the wavy body and the cylinder with bumps still develop at low values of mass damping, even though shedding cannot be detected from the bodies when they are fixed. VIV can be suppressed at significantly lower values of mass-damping than required to stabilize a circular cylinder. (C) 2001 Academic Press.