RANS-VOF modeling of hydrodynamics and sand transport under full-scale non-breaking and breaking waves

Abstract

A 2D RANS-VOF model is used to simulate the flow and sand transport for two different full-scale laboratory experiments: i) non-breaking waves over a horizontal sand bed (Schretlen et al., 2011) and ii) plunging breaking waves over a barred mobile bed profile (Van der Zanden et al., 2016). For the first time, the model is not only tested and validated in terms of water surface and outer flow hydrodynamics, but also in terms of wave boundary layer processes and sediment concentration patterns. It is shown that the model is capable of reproducing the outer flow (mean currents and turbulence patterns) as well as the spatial and temporal development of the wave boundary layer. The simulations of sediment concentration distributions across the breaking zone show the relevance of accounting for turbulence effects on computing suspended sediment pick-up from the bed.