Sediment suspension due to waves
Sediment suspension due to waves
复制标题
波浪引起的沉积物悬浮
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
G. Vittori
中科院分区：
文献类型：
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作者：
G. Vittori
[1] 对源自海底附近的一阶斯托克斯波产生的边界层中的湍流和沉积物动力学进行了模拟。流场是通过纳维-斯托克斯和连续性方程的数值积分获得的，而沉积物轨迹是通过假设单向耦合的简化模型计算的。因此，结果描述了以低浓度和小斯托克斯粒子数值为特征的情况。对湍流涡旋结构与沉积物相互作用的研究表明，当低速条纹开始破碎并产生小的不相干涡流时，颗粒会从床中被拾起并进入悬浮状态，从而增加混合效果。低速条纹在加速阶段结束时靠近海床处产生，此时流速最大，并在循环的减速阶段期间破裂。通过改变控制现象的参数值来研究和量化湍流结构和沉积物特征对拾取和沉积速率的影响。
[1] A simulation of the turbulent flow and sediment dynamics in the boundary layer originated close to the seabed by a first-order Stokes wave is performed. The flow field is obtained by the numerical integration of Navier-Stokes and continuity equations while sediment trajectories are computed via a simplified model that assumes a one-way coupling. Hence the results describe situations characterized by low concentrations and small values of the Stokes particle number. The investigation of the interaction of turbulent vortex structures with sediment shows that particles are picked up from the bed and carried into suspension when the low-speed streaks start to break up and to generate small incoherent vortices that increase mixing effects. The low-speed streaks are generated close to the seabed at the end of the accelerating phases, when the flow velocity is maximum, and breakdown during the decelerating phases of the cycle. The effects of turbulence structure and sediment characteristics on pickup and deposition rates are investigated and quantified by varying the values of the parameters which control the phenomenon.