Role of Front Splitter Plate Gap on the Flow-Induced Vibrations of a Circular Cylinder

In engineering applications, we frequently encounter flow around circular cylinder-type geometries, such as in cooling pipes for heat exchangers, risers and pipelines in oil and gas extraction, storage silos, and buildings in civil engineering. It is widely known that unsteady flow past a bluff body causes alternate vortex shedding and subsequent fluctuating lift and drag forces, resulting in structural damage. It becomes increasingly important to suppress these oscillations to prevent shortening the structure’s lifespan. Amongst various passive suppression devices studied previously, the addition of rigid splitter plates along the horizontal centre-line of the cylinder both upstream and downstream has been found to be quite effective in mitigating transverse vibration. This study aims to understand the previously unexplored effect of varying the upstream gap on suppressing flow-induced vibrations. To accomplish this, the optimization of the gap (g) between the cylinder of diameter D and the trailing edge of the front splitter plate in the range of 0 to 5D has been explored. A two-dimensional stabilized Petrov-Galerkin variational formulation is used to solve the Navier-Stokes equations on an arbitrary Lagrangian-Eulerian moving mesh framework to investigate the response at a low Reynolds number of 120 for reduced velocities of 3–12. The plate length is kept equal to the diameter of the cylinder, and the system is free to oscillate in the streamline and crossflow directions under a low damping ratio of 0.01 and a mass ratio of 6.9. The results of this study will provide valuable insight and aid the development of passive suppression devices for deep-sea structures.