Vortex Induced Vibrations on a Perturbed Cylinder

Engineers and fluid dynamicists have studied vortex induced vibrations (VIV) to develop passive and active methods to reduce oscillations and decrease stress in cross flow dynamic structures. Changes in cross-flow characteristics causes increased vibrations and stress on the structure, leading to higher maintenance costs or degraded mission performance. To mitigate effects of VIV, the design of cylindrical structures in cross-flow can be altered by introducing perturbations on the surface. The aim of the current experimental study is to understand the phenomena of VIV on a perturbed cylinder and compare with a smooth cylinder using a cyber-physical system (CPS). A CPS uses a combination of the physical fluid forces from the flow and cyber implemented forces from a dynamics model to better quantify fluid-structure interaction. A perturbed cylinder will be compared to a smooth cylinder by measuring the force on the cylinder, the amplitude, and frequency of oscillation in an open surface water channel. Additionally, the vortex street in the wake will be analyzed and compared between the cylinders using a dye flow visualization technique. This will enable an improved understanding and correlation between the wake structure and VIV and paves a path forward for control of VIV.