Numerical Investigation on Vortex-Induced Vibration Suppression of a Circular Cylinder with Axial-Slats

The vortex-induced vibration (VIV) suppression of a circular cylinder with the axial-slats is numerically investigated using the computational fluid dynamics (CFD) method for Reynolds number range of 8.0 x 10(3)-5.6 x 10(4). The two-dimensional unsteady Reynolds averaged Navier-Stokes (RANS) equations and Shear-Stress-Transport (SST) turbulence model are used to calculate the flow around the cylinder in ANSYS Fluent. The Newmark-beta method is used to evaluate structural dynamics. The amplitude response, frequency response and vortex pattern are discussed. The suppression effect of the axial-slats is the best when the gap ratio is 0.10 and the coverage ratio is 30%. Based on the VIV response, the whole VIV response region is divided into four regions (Region I, Region II, Region III and Region IV). The frequency ratio of isolated cylinder jumps between region II and region III. However, the frequency ratio jumps between region I and region II for a cylinder with the axial-slats. The axial-slats destroy the original vortex and make the vortex easier to separate. The online amplitude ratio is almost completely suppressed, and the cross-flow amplitude ratio is significantly suppressed.