Forces Acting on Sediment Particles near Bed Under Oscillatory Flow
Sediment transport plays a significant role in the morphological evolution of coastal areas,with the drag force acting on sediment particles being the primary driver of movement.When discrete particle models are used to study the sediment transport,the accuracy of the drag force acting on particles directly determines the reasonableness of calculated sediment transport patterns.Therefore,the investigation on forces acting on sediment particles near the bed(wall)under wave actions is crucial for a deeper understanding of sediment transport mechanisms.In this paper,a particle-resolved model is employed to simulate and analyze the forces acting on one single sediment particle at varying distances from the wall under oscillatory flows of different periods.Simulation results indicate that,for a given Reynolds number,the drag force coefficient decreases with the increasing oscillatory period,while it in-creases as the distance to the wall decreases.When this distance exceeds five particle diameters,the influence of the wall becomes negligible.With a reference to the drag force coefficient of a cylinder under an oscillatory flow,a fit-ting formula is derived for the drag force coefficient of particles under oscillatory flows as a function of the Stokes number and Reynolds number based on simulation results.Furthermore,inspired by the wall correction form of the drag force coefficient of particles in an open channel flow,a wall correction formula is derived for the drag force coefficient as a function of wall distance and the Reynolds number.
oscillatory flowdrag force coefficientnear-bed particleperiod effectwall effect
万方数据
维普
