Numerical investigation of local scour around a vibration pipeline under free surface wave condition

Abstract

A two-dimensional finite element numerical model was developed to predict local scour around a vibration submarine pipeline under free surface wave condition. The flow governing equations are the two-dimensional Navier-Stokes equations which were closed by using the Shear-Stress Transport (SST) k-ω turbulence model. Both suspended load and bed load sediment transportations are considered in the scour model. The Arbitrary Lagrangian-Eulerian (ALE) method was used to track the moving boundaries induced by the vibration pipeline, the free wave surface, and the evolution of the seabed due to local scour. Satisfactory results were obtained after validations carried out. The numerical model is then used to investigate local scour around a vibration pipeline under free surface wave conditions. Present numerical results show that vibration makes the scour depth below the pipeline deeper, scour scope around the pipeline wider.