A NUMERICAL STUDY ON VORTEX-INDUCED VIBRATION OF AN ARRAY OF CIRCULAR CYLINDERS

An array of circular cylinders is a basic unit in many engineering applications, such as buoyancy columns of a semi-submersible platform, risers and cables etc. The vortex-induced vibration (VIV) of the cylinder array is an important phenomenon in engineering applications, which is also of great general interest to fluid dynamics researchers. The complexity of flow separation and the unsteady wakes generated by the cylinder array could induce severe structure vibration. Most of the earlier studies on VIV have been focused on the vibration of a single circular cylinder. However, the VIV of a group of cylinders is still not fully understood. In this paper, a virtual boundary force (VBF) method, which is adopted in an in-house numerical model NEWTANK, is used to study the vortex-induced vibration of cylinder array. In this paper, we discussed three kinds of the initial configurations of the cylinder array, including two side-by-side cylinders, two tandem cylinders and three equilateral arranged cylinders. The trajectory, wake interference and the related hydrodynamic characteristic are discussed in this paper. As a result, we obtained different forms of the interaction between the VIV cylinders according to different configurations.