Control of Flow-Induced Motion in Multi-Column Offshore Platform by Near-Wake Jets Available to Purchase

Vortex-induced motion (VIM) poses a serious challenge in the design and operation of deep-draft offshore platforms subjected to ocean current flow. The objective of the present work is to investigate the suppression of VIM by blowing jet flows at the wake side of a floating platform. To begin with, we first perform a systematic investigation of 2D four-column configuration with and without steady jet flows at Re = 200 and m* = 1. The numerical investigations are carried out for various jet flow velocity ratios (V_jet/U) ranging from 0 to 1 at reduced velocity U_r = 5. From the 2D studies, we observe approximately 30% reduction of forces and displacements for the system with steady jet flow compared to the system without jet flow. We also investigate the effect of angle of blowing jet flow (θ) on the effectiveness of VIM suppression. The idea of jet implementation is extended to 3D model of single square column. The effects of jet positions at the back surface of the single square column are discussed. From the investigations, it is observed that the jet flows at center portion is more effective than the jets at the corners of the column. Based upon the 2D and 3D studies of canonical configurations, the VIV suppression technique by jet flows is employed in a 3D deep-draft floating platform at Re = 20,000.