Effects of free surface modelling and wave-breaking turbulence on depth-resolved modelling of sediment transport in the swash zone

The swash zone is an important region for the coastal morphodynamics. Often, model studies of the swash zone use depth-averaged models. These models typically assume a vertically uniform velocity and sand concentration for calculating the sand transport flux. However, this assumption is not always accurate in the swash zone. In order to investigate the vertical distribution of velocity and sand, we use a depth-resolving model that is able to capture these vertical variations. We simulate the flow and suspended sediment transport induced by bichromatic waves using a 2DV depth-resolving RANS model. Our verification of the model shows that special care needs to be taken to deal with bubbles in 2DV simulations. Furthermore, we show that turning off the (Wilcox, 2006, 2008) limiter for turbulence, increases the modelled turbulent kinetic energy that is induced by wave-breaking, resulting in improved predictions of sediment concentrations. Using the depth-resolving model, we show that the vertical distribution of velocity and sand is far from uniform in the swash zone. The results show that if one assumes vertically uniform depth-averaged velocities and concentrations, one can overpredict the sediment flux by 50%

Rapid imaging of experimental infection with technetium-99m-DTPA after anti-DPTA monoclonal antibody priming

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A depth-resolving model for intraswash hydrodynamics and sediment transport

Numerical studies of sediment transport and morphodynamics in the swash zone generally use numerical models based on the depth-averaged shallow water equations. However, such models still have difficulty predicting the sediment transport (and subsequently morphodynamics) in the swash (see e.g. Ruffini et al., 2020). Depth-resolving models, such as models solving the ReynoldsAveraged-Navier-Stokes (RANS) equations have previously shown to accurately simulate swash hydrodynamics and also sediment transport in the surf zone (Jacobsen et al., 2014). However, applications of a RANS model capable of simulating sediment transport in the swash are limited. In this study, we present preliminary results from our RANS model on sediment transport in the swash