Effect of bottom roughness on sediment transport due to streaming beneath linear propagating waves with an angle of attack on current

Abstract

The effect of bottom roughness on sediment transport due to three-dimensional wave-induced streaming in the seabed boundary layer has been investigated for following and opposing linear propagating waves and current where the wave propagation forms a non-zero angle with the current. Visualizations are given by mean Eulerian wave-averaged suspended flux profiles, as well as the time series of bed shear stress over a wave period. The bedload transport rate along with suspended flux and total sediment transport rate have been presented. For linear propagating waves, the turbulence is induced by the Longuet-Higgins streaming and the classical wave-current interaction. Sediment transport is always in the wave propagation direction for the Longuet-Higgins streaming and increases with decreasing bottom roughness, or as the mean grain diameter decreases.

A review of the state of research on wave-current interaction in nearshore areas

“…It was found that for the medium-sized sand grains, streaming can enhance onshore sediment rates significantly. For fine sand, streaming can reverse the direction of net transport from offshore to onshore direction Afzal et al (2016). investigated sediment transport in the bottom boundary layer, where linear waves propagated at an angle with the current over various bottom roughnesses.…”