Finite Element Modelling of Scour Around a Subsea Structure in Steady Currents

In this study a three-dimensional finite element numerical model is established for simulating local scour around a subsea structure in steady currents. The flow is simulated by solving the Reynolds-Averaged Navier-Stokes equations with a k-omega turbulent model closure. Both suspended load and bed-load sediment transport rates are included in the model. Efforts are made to reduce the computational time associated with three-dimensional morphological modelling. These include the use of wall-function to avoid resolving the near-wall boundary layers, large morphological time step and parallel computing techniques. Scour around a submerged wall mounted vertical circular cylinder is simulated. The effect of the cylinder height on the scour is investigated.