  This paper presents a method for the simulation of scour around arbitrary
offshore structures. It is based on the solution of the
Reynolds-Averaged-Navier-Stokes equations implemented in the OpenFOAM
framework. The sediment is simulated with the help of a Bingham model, which
basically models a solid sediment behavior by introducing a very high
viscosity. The relative pressure used by the Bingham model is estimated with a
new approach based on the solution of a Poisson equation. The position of the
sediment surface is calculated with the Volume-of-Fluid approach using a
high-resolution scheme. To keep the typical wall characteristics without
demanding a fine grid, the common wall functions are transferred to the domain
internal sediment walls. Furthermore, additional modifications are applied to
model a solid sediment wall inside the solution domain. The new internal wall
function implementation is validated with a 2D test case. The results show a
very good agreement to common wall functions and a significant improvement
compared to its negligence. Furthermore the solver is used to simulate the
scour downstream of an apron and the scour around a vertical cylinder in
current. The results are compared to experiments presented in the literature
and show good agreement. The applicability onto arbitrary structures is
demonstrated by applying the solver onto a vertical cylinder with a mudplate.
The current development state is able to resolve all important physical flow
and scour phenomena. The results also unveil that modeling of the suspension
and the treatment of the internal wall need additional attention.
