Effect of Wave Skewness and Sediment Particle Size on Sediment Transport Due to Combined Wave-Current Seabed Boundary Layer Streaming

Abstract

The effect of wave skewness and sediment particle size on near-bed sediment dynamics and transport owing to wave-induced streaming is examined in this study. Here, wave-dominated flow over a flat rough bed is studied, with wave propagation forming a nonzero angle with the current. It was observed that the increase in wave skewness increases the mean sediment transport, which is consistent with prior findings for the particular situation of horizontally uniform Stokes forcing. The mean sediment transport beneath combined second-order Stokes waves and current has been investigated for fine, medium, and coarse sand, respectively. Due to inertia, both the mean bed-load vector and the depth-integrated suspended flux vector are less rotated (relative to the wave propagation direction) for coarse sand than for fine sand. The mean bed-load transport is largest for coarse sand, whereas the mean suspended sediment transport is largest for fine sand.