On the hydrodynamic response and slamming impact of a cylindrical FPSO in combined wave-current flows

Abstract

Owing to the lower construction and transportation costs, cylindrical floating production storage offloading (CFPSO) has received extensive attention in the industry. Currently, attention has primarily been focused on the damping performance of heave plate while few studies have touched upon hydrodynamic characteristics under complex combined wave-current condition. In this paper, we numerically investigate the hydrodynamic response and slamming impact of a CFPSO under combined wave-current flows. The active wave generating-absorbing boundary condition (GABC) along with the buoyancy-modified k-omega SST turbulence model are utilized to generate high-precision waves and current based on the open source computational fluid dynamics (CFD) framework OpenFOAM. A self-developed six degree of freedom (6DOF) motion module is used for solving rigid body motion and updating mesh motion. The numerical results of motion response and impact pressure are compared with the experimental data to verify the accuracy of present simulations. The correlation between impact pressure and relative wave elevation and wave velocity is analyzed and three types of slamming events have been identified. The flow fields such as vorticity, pressure and streamlines in the vicinity of the CFPSO are also presented and discussed, which provides a reference for structural design for the CFPSO under complex sea conditions.