NUMERICAL AND EXPERIMENTAL DESCRIPTION OF THE FLOW, BOUNDARY LAYER AND BED EVOLUTION IN BORE-DRIVEN SWASH ON A COARSE SEDIMENT BEACH

Riccardo Briganti, Nicholas Dodd, Dubravka Pokrajac, Tom O'Donoghue

Abstract


The paper presents the results of a comparison between a fully coupled numerical model for the hydro- and morphodynamics of the swash zone. The model solves simultaneously the Non-Linear Shallow Water Equations and the Exner equation for the bed updates. The model uses the simple Grass formula for the sediment transport and the momentum integral method for the bottom shear stress prediction. The laboratory tests were carried out at the University of Aberdeen swash facility and aimed at studying the hydrodynamics and sediment transport of a single, bore-generated swash event. The comparison is carried out in terms of water depth and horizontal velocity (depth average and profiles) and sediment transport. The model performs well in predicting these quantities, above all during the run-up.

Keywords


swash-zone morphodynamics; coarse sediment beach; numerical modeling; TVD numerical schemes

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