Simulation of Vortex Induced Vibration Around Offshore Pipeline

The flow around a pipeline laid on the uneven seabed causes Vortex Induced Vibration (VIV), which in turn increases significantly the potential of fatigue damage of a pipeline at the free span sections. In general, the Morison equation is employed for estimating the averaged hydrodynamic force acting on an offshore structure; however, to elaborate the vibration forces due to VIV effects, simulation of vortex shedding and its induced time dependent pressure and velocity distribution is very essential. In this paper, it is intended to provide a numerical model to simulate the VIV effects on the offshore pipelines, by calculating numerically the vortex shedding and its induced turbulent pressure and velocity field. Finally, the unsteady pattern of dynamic drag force is obtained by the model, which is constructed based on the Reynolds Averaged Navier-Stokes (RANS) equations in conjunction with a standard k–ε turbulence model for turbulence closure.