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 cros s-sectional body with a sinuous axis and a circular cylinder with hemispher ical bumps attached. A wide range of Reynolds number has been studied, up t o a maximum value of 10(5). Suppression of vortex shedding and drag reducti ons up to 47% have been observed for the body with a sinuous axis. Drag red uctions of about 25% and suppression of vortex shedding have been recorded for the cylinder with bumps. VIV experiments over a range of the mass dampi ng parameter from 2 x 10(-2) to 5 have shown. that amplitudes of oscillatio n 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 w hen they are fixed. VIV can be suppressed at significantly lower values of mass-damping than required to stabilize a circular cylinder. (C) 2001 Acade mic Press.