Scour at the foundation of offshore structures is an important engineering problem. Accurate numerical modeling of transient sediment transport will allow to predict erosion patterns and to design more efficient structure foundations. In this work, the Reynolds Averaged, Two Phase Flow Equations are used to model water and sediment as a mixture of two inter-penetrable, continuous phases in an Eulerian frame. These equations are solved using a finite volume scheme on an unstructured 3D mesh. The fractional step method is used to ensure the incompressibility of the mixture.