SEDIMENT TRANSPORT UNDER (NON)-LINEAR WAVES AND CURRENTS

Proceedings of the International Conference on Coastal Engineering

Khaled A.H. Ramadan⁴  Irene Katopodi⁵  Jan S. Ribberink³  Sandro Longo¹  Ria Koelewijn² 

[1] University of Florence, Department of Civil Engineering;Delft University of Technology;Delft Hydraulics;Hydraulics & Sediment Research Institute;Democritus University of Thrace, Department of Civil Engineering

关键词: sediment transport;    nonlinear waves;    current;   

DOI  :  10.9753/icce.v24.%p

学科分类：建筑学

来源: Coastal Engineering Research Council

【 摘 要 】

Two series of experiments were carried out in the Large Oscillating Water Tunnel of Delft Hydraulics, which was recently extended with a recirculation flow system. Combined wave-current boundary layer flows were studied with a mobile sand bed in the sheet flow regime. Detailed intra-wave concentration and velocity measurements were carried out and revealed a three-layer system, i.e. a pick-up layer, a sheet flow layer and a suspension layer. In the suspension layer time-lag effects of the sediment concentration led to sediment fluxes in upstream direction. The suspended sediment was more confined to the near-bed region than according to diffusion theories, most likely due to turbulence damping. The horizontal timedependent and net sediment fluxes were concentrated in the sheet flow and pick-up layer. Measured net sediment transport rates could be described as a linear relation with the third-order velocity moment near the bed.

【 授权许可】

Unknown