UNDERSTANDING AND MODELLING WAVE-DRIVEN MIXED SAND TRANSPORT

This paper presents new net transport data from the STENCIL full-scale wave flume experiments with a sediment mix of a fine (0.21 mm) and a coarse (0.58 mm) sand fraction. These and existing mixed sand transport data from full-scale oscillatory flow tunnel experiments were used to validate the SANTOSS practical sand transport formula, which includes size-selective transport mechanisms and hiding and exposure effects. The STENCIL data show a strong effect of the sediment mix on the bed form regime and net transport rates. The SANTOSS formula predicts the flow tunnel net sand transport data well, and does a reasonable job in reproducing the net sand transport per fraction in the mix. The new STENCIL net transport data are generally underpredicted. In further research the SANTOSS formula will be further tested and improved using more detailed STENCIL data of flow and sand transport processes.