A Study on the Vortex Induced Vibration of a Cylindrical Structure with Surface Bulges

Inspired by the cactus in nature, a cactus-like cross-sectional structure was proposed to achieve VIV suppression. The of elastically mounted cylinder realized based on ANSYS Fluent and User Defined Function (UDF). dynamic motion solved single-step time integration algorithms Newmark-β method. in-house code first validated studying 2DOF circular with small mass ratio over range U*=2~13, results agree well published literature. Then, performance surface bulge suppression studied four different coverage ratios (CR) were considered, i.e., 0%, 20%, 33%, 40%. bulged can be effectively suppressed. CR20 performs best efficiency streamwise transverse direction are 44.6% 63.1%, respectively. mechanism is shift separation point shear layer vortices form between bulges.