Experimental studies of passive control of vortex-induced vibration

Measurements of vortex-induced vibration of a plain circular cylinder and cylinders fitted with strakes and bumps are presented. Experiments were carried out in water with mass ratios in a range from about 1.5 to 5.5 and combined mass and damping values between about 2 x 10(-3) and 7 x 10(-3). Reynolds numbers were within the range 10(3) to 10(4). Although the wakes of fixed cylinders with strakes or bumps show little or no evidence of regular vortex shedding it was found to establish itself across a range of reduced velocity when the mass and damping parameters are sufficiently small. However, the amplitudes of vibration were less than those for a plain cylinder. It is observed that the modes of shedding found for an oscillating plain cylinder are also present for a responding cylinder fitted with vortex suppression devices. (C) 2003 Published by Elsevier SAS.