Rigid cylinder with asymmetric roughness in Flow Induced Vibrations

Flow Induced Vibrations (FIV) of a single, rigid, circular cylinder with one-sided PTC (passive turbulence control) are investigated experimentally and numerically for Reynolds number 30,000 ≤ Re ≤ 110,000. Comparisons of response are made between symmetric and one-sided PTC-cylinder. For the one-sided configuration, different PTC location angles for the one-sided configuration are applied to initiate the asymmetrical FIV, which is studied in detail. A user-defined function, combined with dynamic-mesh is established in a commercial solver. At different flow speeds in the vortex induced vibration (VIV) and galloping ranges, flow-field details and displacement time-history at selected positions of the cylinder are presented and discussed. Conclusions of the asymmetrical oscillation and the effect of selective roughness are drawn with respect to the flow speed, damping ratios and the PTC locations angle at the end.