Laboratory experiments for wave-driven sand transport prediction

Since the first NCK-Days 20 years ago, a significant body of large-scale laboratory experiments on wave-driven sand transport has been conducted in oscillatory flow tunnels and large wave flumes. The experiments have yielded measures of net sand transport rates for a wide range of flow and sand conditions and have provided insights that have informed the development of practical predictors for sand transport in oscillatory flows and under waves. An overview of these experiments and a commentary on some of the important insights and quantitative results is presented. Particular attention is given to unsteady aspects of the sand flux for ripple regime and fine sand sheet-flow conditions, the role of flow acceleration on bed shear stress and net transport, and the differences in ne transport and transport processes occurring in tunnel oscillatory flows and occurring under progressive surface waves.