SEDIMENT-CLOUD BASED MODEL OF SUSPENSION OVER RIPPLE BED DUE TO WAVE ACTION

Abstract

Sediment cloud, which is released periodically from the crest of ripples, plays a very important role in suspension over a ripple bed under the wave action. By considering the special role of the sediment cloud, suspension is divided into two subprocesses: (i) the transition process from bed-load motion to suspension as the entrainment of the sediment cloud; and (ii) the diffusion process of suspended sediment released from the sediment cloud. The trajectory of the sediment cloud is calculated by Lagrangian approach in the flow field solved by k-e model of turbulence. The suspended sediment concentration is simulated by solving a diffusion equation which has the source term due to sediment cloud.